Travel with a purpose: a look at nonprofit tour operations.

Habitat For Humanity

The Global Village program is a series of short-term trips designed to take volunteers to Habitat's programs across the world. By living and working with the host community, participants have an opportunity to witness and contribute to efforts to eliminate substandard

Destinations: Africa, Asia/South Pacific, Central America/Caribbean, South America, Europe/Central Asia and North America.

2003 Trips: 46 trips scheduled for 2003, including Tanzania, Zambia, Kenya, India, Fiji, New Zealand, Guatemala, Costa Rica, Guyana, Romania, Kyrgyzstan, Alaska and more.

Cost: Ranges from $1,200-$1,800 for a 10-day trip to Central America/Caribbean to $2,000-$3,800 for a 12-20-day trip to Asia/South Pacific to $2,800-$4,000 for a 18-30-day trip to Africa.

Tax Deductible: Depends on the nature of the trip. Travel expenses incurred on a trip, that is mostly charitable in nature may be deductible, though the monetary value of volunteer time is not.

Heifer Project International

Study tours aim to connect travelers with Heifer's mission of teaching families all across the world to become self-reliant through the gift of livestock. Much time is spent visiting with families who are being helped. Travelers may circle dance with one of Thailand's Hill Tribes or milk the family goat in Uganda. There's also time to learn about the country's history and culture.

Destinations: Trips are planned each year in Heifer's five program regions: North America, Latin America/Caribbean, Central/Eastern Europe, Asia/South Pacific and Africa.

2003 Trips: 12-20 trips per year, including Thailand/Cambodia, China, Ghana, Poland, Vietnam, Uganda/Rwanda and Russia.

Cost: Ranges from $l,800-$3,500 for a 10-14-day trip to Latin America/Caribbean to $3,200-$4,500 for a 14-21 day trip to Asia/South Pacific tours to $4,000-$5,000 for a 17-24-day trip to Africa.

Tax Deductible: Yes

Sierra Club Outings

Travelers go to all corners of the world. Volunteers primarily scour, plan and propose all Sierra Club trips. The group is considered an outdoor outfitter in the travel industry

Destinations: Everything from U.S. national parks to African safaris.

2003 Trips: More than 350 trips per year are offered, including 62 international trips. Siberian Russia is one of the newest trips offered. On average, 4,000 Sierra Club members travel on these outings.

Cost: Range from $1,500-$5,400 for a trip to the Caribbean to $4,000 for a trip to Africa. Average trip is $2,000. (Trips are 10-21 days and do not include airfare.)

Tax Deductible: Sierra Club Outings are not tax deductible. because 10 percent of the organization's money goes to political lobbying. Some service trips, where travelers volunteer their time at specific environmental projects, are tax deductible.

World Wildlife Fund

Travel enhances members' understanding of natural systems and conservation challenges. WWF offers trips to areas of the world rich in wildlife that highlight the organization's goals. WWF pioneered the concept of using tourism to support conservation -- the key idea behind "ecotourism."

Destinations: All over the world, from Alaska to Antarctica to Galapagos to Nepal.

2003 Trips: 30 trips scheduled, including Galapagos and Africa, which are very popular.

Cost: Ranges from $1,995 for a Baha trip to $34,000 for a three-week, private jet trip around the world. Trips are typically 9-14 days.

Tax Deductible: No

National Geographic Expeditions

Expeditions are led by National Geographic experts, including anthropologists, archaeologists, biologists, explorers, historians and naturalists. Expeditions are taken all over the world, including access to special events, scientific installations, archaeological digs and to private homes.

Destinations: All over the world, including Africa, Antarctia, Asia/South Pacific, Europe, Latin America/Caribbean and North America.

2003 Trips: 50 trips scheduled, including Kenya Family Wildlife Safari, Mysteries of Ancient Egypt, journey to Anarctica, Mound the World, Inside Japan, World War I, Espionage and the Spy Capitals of the World and more.

Cost: Ranges from $4,950 for a 11-day trip to Greece to $6,995 for a 14-day trip to Africa to $39,950 for a 25-day trip around the world. Prices do not include airfare.

Tax Deductible: No

Smithsonian Journeys

Travelers explore countries and their cultures with a Smithsonian expert. Since group sizes are kept small, itineraries can be flexible.

Destinations: All over the world, including Africa, Antarctica, Asia/South Pacific, Europe, Latin America/Caribbean and North America.

2003 Trips: About 140 international trips, including Christmas in Prague, Gardens of the Caribbean, Enchanting Tahiti and French Polynesia, France Through the Ages, Italian Automotive Design and History, Lands of the Eastern Baltic, Tuscan Walks and more.

Cost: Ranges from $2,995 for 13-day trip to France to $7,890 for a 20-day trip to Indochina to $9,840 for a 15-day trip to South Africa.

Tax Deductible: No