Volunteer World This online directory includes 1500 NGOs in over 75 countries. You can search by country or interest (everything from wildlife research to teaching, medical internships to marine conservation). Their site includes the full range of prices from free to luxury, and all volunteer periods from 1 to 50 weeks. Plus, you can apply right on the site to volunteer.

PAVA Foundation (Programa de Ayuda a los Vecinos del Altiplano) works in the Guatemala highlands, helping communities obtain everything from women’s education to water. Thanks to active volunteers (some of whom contribute during volunteer vacations), almost 100% of donations can go to the projects.

SHARE GUATEMALA. This secular, apolitical nonprofit that has worked on development issues in Guatemala since 1987, runs “voluntours” and invites tourist groups to participate in their programs on education, food security, women’s microcredit, and family health. For more information email Keila, Kaelvalle@shareguatemala.org. Learn more

Global Vision International pairs interested travelers with expert trainers, so they can volunteer with one of 150 projects run by nonprofit organizations and NGOS in 30 countries. Projects include social, educational and community development work as well as environment and conservation programs. Learn more

I-to-I Meaningful Travel. This travel company sells courses in Teaching English as a Foreign Language and offers TEFL job placement around the world. They also send volunteers on trips to work on 500 projects on 5 continents—perhaps working with orphans in Kenya, or Hill Tribe children in Thailand. Learn more

Want to join a team of two or three who help women's groups develop skills to improve their economic situation? Cross Cultural Solutions is a nonprofit that places volunteers in locally designed and driven partner projects in Africa, Latin America, Russia, and Asia. Year round programs provide health care services, education and support community development. You can participate for 1 week up to 6 months. Fees include room and board but not airfare, and start at $2175; they vary by program duration. Cross Cultural Solutions will survey your skills and interests prior to placement and provide in-depth orientation about culture and customs, plus language assistance. Learn more

The definition of sweat equity: build a house from the ground up. Habitat for Humanity builds low income housing in 80 countries. Their Global Village Work Trips send teams into villages to work side by side with local people. Volunteers travel, work, live and eat together, often in primitive settings. Fees start at $1100 and vary by location. Learn more

Earn academic credit for international work in Latin America and Spain that’s organized through AmeriSpan's Volunteer/Internship programs. Recent volunteers worked in a Guatemala woman's educational cooperative, a Mexico women's crisis center, an Ecuador women's prison, a Peru education center for girls, an Argentina program for street children, and Bolivian orphanages. Learn more

Village Volunteers. This organization collaborates with NGOS to support community leaders in Kenya, Ghana, India, Nepal and Seattle who empower local people, rely on indigenous resources, and build on cultural traditions to implement sustainable solutions for community survival, education and growth. All projects are initiated, executed and managed by local people. If you’d like to volunteer, contact Shana Green, Founder and Executive Director. Learn more

Global Volunteers offers 180+ volunteer vacation opportunities in 20 countries on 6 continents. You might tutor grade-schoolers, share life stories with elderly women, stock the library. Average stay is 1-3 weeks. Learn more

Kosrae Village. Katrina Adams, from California, co-founded this Micronesian eco-resort a dozen years ago. You can join a team of volunteers who drive for two weeks to collect data to help keep the indigenous coral reefs healthy. Learn more

Put your work experience to work in developing countries where any Professional experience is precious. The World Guide and Information Network directory is available via the Green Volunteers website. The directory describes short, medium and long term options all over the globe.

Irma Turtle was a VP at Ogilvy and Mather Worldwide before she found her passion in life: tribal peoples. Her company, Turtle Tours, offers trips to indigenous communities. Her nonprofit organization, Turtlewill, can arrange for you to travel with them as a healthcare volunteer (no training required) or a staff assistant.