Habitat for humanity seems like a good one, building homes for people not so well off, its a great cause, and they have programmes in loads of different countries...

Intrepid Travel are fantastic and have partnered up with some long-standing volunteering organisations so you can do 2 to 6 weeks or longer in 10 countries, all to do with community development so that the volunteer benefits personally from the experience and the host communities do too (which often gets overlooked with some volunteer operators)....

This is a tough question to answer. Everyone volunteers for different reasons. Do you want to help a local family? Some animals? An international organization or a small local one?
Two organizations I frequently chek out are i-to-i - to.i.com-www.i-to.i.com and The Earthwatch Institute - www.eartwatch.org they both have a wide range of volunteer options.
Of course if you're from the US, the Peace Corps - www.peacecorps.gov is always an option for you. (I wish we had something similar in Canada...anyone know of such a thing?) Finding the best volunteer tour requires a lot of research, as it is a very personal thing. In Canada I read Verge magazine - www.vergemagazine to see what different organizations are doing.
Hope these ideas and links help some people!

Hmm, sorry some of those links went weird on me!

personally I think i-to-i is a rip off!
 
try: www.ecoteer.org
or www.ecoteer.com (1 may not work)
http://www.volunteersouthamerica.net/
 
http://www.ecuadorvolunteer.org/
 
 this has some free and paid projects.

also all Intrepid travel tours and volunteer programmes are fantastic! they are awesome :)

I've heard great things about i-to-i, Intrepid and Earthwatch though it seems they all target different audiences. 

Ya, i-to-i may not be the best bang for the buck, but some people seem to like them. The Intrepid options do look very good too! A couple similar companies I've seen are World Expeditions and Gap Adventures, but they do not have as many options as Intrepid.

I just discovered Responsible Travel - www.responsibletravel.com - they have a ton of volunteer options, anyone know much about them?

I also can recommend www.flyforgood.com - they are making a massive volunteer travel portal to make it easier to find the ultimate trip for you.

Make sure when you think about volunteering abroad you ask the operators a bunch of questions - I love the list that GeckoGo put up:

"What questions should I ask or what should I look for in choosing a company or tour? Here are some questions to get you started:

• What kind of toilets are there?
• Will there be hot water?
• Is food included?
• What kind of language skills do I need?
• Where does the money go?
• Will there be an orientation session?
• Do I get an airport pickup? Is transportation included?
• Does this organization have an in country staff?
• Is your first night organized, or do you need to do that yourself?
• Can you speak to a past volunteer?
• When’s the best time to go?
• Is the organization for profit or not for profit?
• Who’s signed up for your dates of travel, and are they of what age?
• What kind of organization are you? Tourism focused first or community focused first?"

Sorry, I'm new at this - hopefully the link works this time =) www.flyforgood.com

I also recommend Santa Lucia Ecuador - great project that I loved volunteering at.

Another tour/vounteer company is Imaginative Traveller (www.imaginative-traveller.com) They work with i-to-i and also do some neat volunteer trips, especially in SE Asia, like working with the Pandas in China or elephants in Thailand.

If you want to volunteer as a professional VSO is a good organization.

VSO and Peace Corp both I believe - use graduates or at least professional or tradespeople and they pay a local salary.
I badly needed a couple of volunteers to manage the project I have started in SW Uganda - I approached VSO & learned the project itself had to provide accommodation with a minimum of bedroom living room kitchen private toilet and shower AND pay a salary of about twice what we would expect to pay a local qualified person (they are always available but we had no income to pay one) Thus taking jobs AWAY from nationals.
The big tour companies such as mentioned above - do your research carefully and decide for yourself exactly where your large fee is going....we charge £50 a week (negotiable) for accommodation & food & that gives a profit in most developing countries. The rest of the large fee some are charging - will it go on what you are going to do?
Many projects have to use volunteers money to actually do the project - especially if its new build or starting income-generating businesses - its only education that can be done with no funding.
I guess some of these "fees" are paid to managers to babysit teenage GapYear people but do you really need that - is it not about finding your feet and becoming self motivated and self-reliant??
By the way I must write anopher thread - someone recently said to me they they woyd love to do it but they thought volunteering was only for teenagers!!! I was born before the end of WW2 so work that one out!
Ann www.ugandalodge.com

The projects we run in Cambodia (www.pepytours.com) are an example of a smaller grassroots organization doing volunteer projects which are directly integrated into more long-term work.  For me, that type of volunteer tourism has been more appealing that going with a large volunteer tour operator as, with many of those, there seems to be a lot of distance between the people selling the product and the communities which are supposed to be served.

When choosing a volunteer tour operator, I would ask these types of questions:

1) Where is my money going?  Is a portion of the fee going to the project I am working on?  How much?  Is that amount transparent or is the organization honest and upfront about that.

2) What is the ongoing relationship with the program?  How will your work be integrated into any longer term impact?

3) Is there a list of people who have done the project before you that you could contact to get first hand advice from?

4) How is the REST of the trip designed?  Was there care to choose locally owned hotels and suppliers?  If we are looking to give back to the areas we are visiting, there is so much more we can do that just the volunteer portion.  The REST of our trip, and how/where we spend our money is just as if not more important than where we give our time.

I think it is important to note that, unless we are coming into a very specific project which requires specific skills we have, it is unlikely that our volunteer time is going to be the cause of any large impact we have during a short trip.  On the other hand, the impact we are able to have once we leave, when we travel in the future, how we purchase in the future, what we read in the future, when we teach others about what we have learned - THAT is a much larger and more lasting impact.  In addition, if we choose to partner with a group that has long-term relationship in the area, they will likely be able to integrate us directly into a more ongoing project so, for example, rather than just building a fence and leaving, we are building a fence around a community garden which is going to be used by a childrens environmental education project which has a two year plan etc etc.... in THAT case, two years later, when we get emailed pictures with the fence we helped to create as part of a life-changing and educational program for children we can really see how our efforts were maximized and integrated into long-term change.

I think ecoteer is a good one.I like wwoof as well if you like farming and organic food.You can also volunteer with an organization.I have volunteered in a kibbutz and really like it.

A good experience for someone can be a bad experience for someone else. It mainly depends on you.

But for sure, I wont volunteer with an organization I have to pay or when the fees are too high.

Good luck Grace

I loved volunteering with Habitat for Humanity in Comanesti, Romania.  They really found projects that had an impact, got us involved with the community and local volunteers, and gave us opportunities to embrace the culture!  It was on the expensive side, but a lot of the money goes toward the building materials for the houses you are working on.  I fundraised to help make the trip a little more affordable and it was definitely worth it!  

I am stephen wakoyo owuor and I love the people and the idea that we might make a difference and for this am looking for a good organizatio that can give me an opportunity to volunteer and work a broad.

I've heard good things about the SWAP program, though I haven't tried it myself. It helps Canadians get set-up with working visas in certain countries for 1-2 years and provides people from other countries the chance to get a Canadian work visa, but i know that there is an age limit and it's only open to people from certain countries. Worth checking out though! www.swap.ca

I've also recently joined the Joints in Motion team that's heading to Athens for the marathon in October 2010. The program requires you to raise a certain amount of money for The Arthritis Society (either through fundraising or by paying it yourself) and you can complete marathons and other races at various places around the world. There are some great options this year - Disney in Florida, the Caymen Islands, Athens, and even a 10 day trek in Nepal! In the past there have been trips to Switzerland, Italy, Costa Rica, Peru and China, to name a few. It's a great way to travel and raise money for a great cause. We have the option to extend out trip in Athens, so once the marathon is over (if I can still move!) we can spend a week or two exploring before coming back. It's not volunteering and you don't get a visa, but it's still supporting something worthwhile.

There are hundreds of agencies that sponsor global volunteering. I've worked under a dozen of them on a variety of short-term projects. Global Volunteers, Cross-Cultural Solutions, Global Citizens Network, Earthwatch are just a few. The best resource, though, is a book called Volunteer Vacations by Bill McMillon et al, which gives brief descriptions of 250 organizations operating volunteer programs around the world. It will get you started and you can research further on specific websites. Volunteering gives you a totally different view of a country from what you experience as a tourist. Go for it!

I did some volunteer work with Real Gap Challenge and had such an amazing time. The first was a month in the Galapagos where I worked in a conservation centre for Galapagos Tortoises and the second was in Bolivia, working as a classroom assistant in a school. It's a great company because they organise everything for you but you still feel like you're doing it on your own and you get to experience a country in a really authentic way ie stay with local families and live as the locals do. They have volunteer placements all over the world with a range of different projects, depending on what your interests are.

Have a great time, wherever you go!

I know I small but kind organsacion in Cusco, Peru
www.volunteering-peru.com
they support small local projects and don´t charge a high insciption fee.

I had a wonderful experience volunteering abroad with GoEco. You can find amazing projects on their website at www.goeco.org ---- There's a wide range, including projects for the family!
The staff is also super nice and helpful.

Hello ca anybody now sites which we can registered with,i means which does not need money to register like WWOOF , couchsurfing, idealist, encounteer.com , etc. We would like to advertise our project with them,
please help

Dear Sir/Madam
         My name is Believe Doe Dartey a Social worker in Ghana Have worked with alot Voluntary organisations in Ghana .I have now formed my own organisation called the world class Volunteers Network ,We organize voluntary work camp in various community in Ghana to help in their Developmental effort .currently  we are seeking partners and volunteers to work with us to propagate the voluntary concept worldwide .
i hope you will bid into my vision so we will come together to work for the betterment of mankind.
  This is  our website www.wcvnonline.org
Thank you God Bless.  
Believe Doe Dartey

Dear Sir/Madam
         My name is Believe Doe Dartey a Social worker in Ghana Have worked with alot Voluntary organisations in Ghana .I have now formed my own organisation called the world class Volunteers Network ,We organize voluntary work camp in various community in Ghana to help in their Developmental effort .currently  we are seeking partners and volunteers to work with us to propagate the voluntary concept worldwide .
i hope you will bid into my vision so we will come together to work for the betterment of mankind.
  This is  our website www.wcvnonline.org
Thank you God Bless.  
Believe Doe Dartey

Thank you Doe, for the work you are doing over there!I am stephen from kenia working with the community in kenia.I have also done community and Development.We are also seeking partners with many people around the world.Here is our webpge www.freewebs.com/kich/.
we have been receiving many volunteers in kenia and we can join our hands together ,if any of them would like coming to ghana ,we will send them to you,
can you send me you phone number?
stephen,
God bless.

Here are some great directories of volunteer and teach abroad programs, where you can also read reviews from past participants.

Teach Abroad: http://www.goteachabroad.com/
Volunteer Abroad: http://www.go-volunteerabroad.com/

Dear Doe Dartey B.
I have register with your organization you gave me as parteners and I hope you will include me in the website sooon!!!
Thank you and May God bless you Mr Doe.
stephen from kenya.

Hello everyone! You can register as a potential development volunteer and apply for your matching projects to volunteer in Kenya with Prophet Reward Foundation Charity Beyond the Borders Community Trust Volunteers (PRF-BBCTV) program http://volunteerabroadinafrica.wordpress.com/volunteer-in-kenya/

Hey, here is our webpage www.freewebs.com/kich/ could you partner with us.

This is one of the ones I have bookmarked to volunteer with in a year or two:
 Peru's Challenge.
http://www.peruschallenge.com/
I love that the trek to Machu Picchu is also included in the volunteer fee, it is something I have always wanted to do anyway.

There are tons of organizations for volunteering in Central America, but I found Green Life Volunteer and volunteered through them in Costa Rica. They were amazingly personal and I felt well taken care of. The turtle conservation project was just amazing. I would highly recommend going with these guys if you're interested in volunteering in Costa Rica!

www.glvolunteers.com
Green Life Volunteers Costa Rica

:)

If Costa Rica is your destination for volunteering, you can't do better than the Costa Rican Humanitarian Foundation, Apartado 458, Santa Ana 6150, Costa Rica; (506) 390-4192 or (506) 282-6358; http://www.crhf.org (www.crhf.org/). Volunteers work for any time span on any of fifty-plus diverse projects throughout the country. Low fees. Gayle Nystrom, an American, founded it and runs it with amazing personalization. I've done different work for her for 2-3 weeks each, twice. She sets up your home stay and even helps you organize weekend excursions. Will set you up for any length of time in almost any volunteer activity you can imagine.

"www.oulfakirTours.page4.me " offers: a large tours throughout Morocco, private tours in Morocco, Morocco desert adventure, new year's eve in Morocco Easter week in the desert of Morocco, Morocco desert trip, Trekking Desert Morocco Camel , f expiditions desert, Marrakech desert tours, travel between Ouarzazate and the desert ... visiting the Kasbah, mountains and oases in Morocco tours, walking in the desert. large camel tours around the dunes of Erg Chebbi, tours of the Sahara Desert in a 4x4 "oulfakir Tours" We also organize nights in Berber tents in an oasis of magic in the Sahara Desert in Merzouga Dunes and organize tours for 2, 3, 4 days in the desert, "oulfakirTours" invite you to experience the beauty of this body and embrace the infinite silence of the Sahara desert.

Planning a Volunteering Trip to India, you have questions about projects, travel, stay, experiences.... | Join BB Group: IndiaTravel | BBPin: 26C48D71 | Please Mention - IndiaTravel - when sending request to join | Share your experiences with like minded people, respond to queries, help and look for support | Cheers | IndiaTravel

In so many instances volunteers are paying a lot of money for a project that turns out to not offer exactly what their website suggests. This big companies are very profit orientated. I found a company,  Yevu Volunteers, which are smaller and offer a more personal service. With them, you can select a project from a list, or even create your own project with them, to suit you! www.yevuvolunteers.com

Guess this is going to people who were looking a long time ago for volunteering - but you can still consider a holiday with a difference without spending a fortune Please see www.ruhanga.com  we can organise volunteering in Uganda where the only cost is £70 per week for all your food and accommodation. You can be sure that whatever your sills and interests, your help will be much appreciated by the local community and  if you wished, you can also add on safaris visits to places of interest and a way to go gorilla trekking at very reasonable cost, but knowing any small profit will be helping the village community projects (education, clean water, health etc)

Please consider the negative impacts that can come from volunteering with children in the growing, and harmful, practice of short term orphanage volunteering or orphanage tourism. Two resources on this topic have recently come out out of Cambodia:  http://orphanages.no/ , http://www.thinkchildsafe.org/thinkbeforevisiting/ , and a global site which works in this space is http://internationalchild.org/   Pass them on!

This is really true Daniella, I heard of one organisation (Projects Abroad) that send someone to an orphanage in Cambodia, who is now in prison for defiling some of the children in it. 

Hello everybody! 

Hello Joan S. Why can't you try on this http://www.prophetrewardfoundation.org/index.php/volunteer-opportunities to volunteer abroad Africa in Kenya? For more information email hdvkenya@gmail.com

Hello joan S. am running a good organization in Kenya , very cheap.for more information visit www.freewebs.com/kich/.
We  are connected to many volunteers site around the World and you can email me on kichcentre@yahoo.com.
The project is located on the famous lake Victoria.

“The Little Big Project” is a Volunteer Tourism competition funded by the Tourism Authority of Thailand (TAT), to inspire worldwide travelers to take a Volunteer vacation in Thailand.  
This will give you an opportunity to do something meaningful while on holiday, You will be amazed how little can make such a BIG difference, and to have a life changing experience for yourself and make a better world for others.
__________________________ 

Koh Talu, Koh Singh, and Koh Sang are three picturesque islands located in the northwest of the Gulf of Thailand, and they are part of a marine restoration project currently underway there. Overfishing and the use of harmful methods such as dynamite fishing and cyanide fishing, causing damage to the coastal ecosystem, have affected much of the beautiful sea life and coral reef.
In order to combat this problem, organizations like the Marine Science Activity Conservation Foundation (MSACF) and the Coral Reef Restoration Project of Koh Talu Island Resort have undertaken campaigns to raise awareness of the importance of coral preservation.
The latter has developed a technique for transplanting coral which they’ve been using successfully for over 10 years, and which is sometimes open to travelers as a voluntourism opportunity; and, the resort’s owner runs the country's largest privately run hatchery and nursery for hawksbill turtles.
Koh Talu islanders have allocated an area of the island for the nursery, and the Royal Thai Navy has an active role in the program as well. Veterinarians from the Department of Marine and Coastal Resources who are experts in the hawksbill turtle also consult on the project, providing advice on egg laying, incubation, and nursing.
Volunteer (www.thelittlebigprojectthailand.com/" style="font-family: arial; font-size: small;)

Hello Joan S.

Belize is just a two-hour flight from Houston or Miami.  Also, English is the language spoken in the country so you don't have to worry about miscommunications.  Belize is on the Caribbean in Central America and has the world's second largest coral reef, Mayan temples, and many great volunteering opportunities.  One of the best things about this little country is the incredible diversity and the ability to actually do it all!  I have been working with a local company out of Cayo, Belize.  Get in touch with me if you want me to hook you up.  They run specials on group travel.  mebelize@yahoo.com  JC Connect