How do volunteer vacations work?
In general, volunteer vacations are unpaid opportunities provided by a variety of nonprofit organizations that are devoted to worthwhile or charitable causes. To take part in a project, expect to pay for your own travel expenses and, if need be, supplies, in addition to a fee paid to the agency you'll be working with. Fees can range anywhere from a few dollars to a few thousand, and usually cover things like housing, coordinators, escorts, meals and on-site training.

Volunteer opportunities vary greatly, offering a range of living situations and degrees of comfort. For instance, some projects might require you to camp out and cook your meals, while others may provide room and board. Longer-term ventures may even provide you with a stipend. Some well-known organizations that offer volunteer vacations include the American Hiking Society, the Sierra Club and Doctors Without Borders. Opportunities typically last anywhere from a week or two to several months, though there are some that require a much longer commitment.

What are my options?
The possibilities span an enormous array of choices. People who are interested in environmental issues can help build trails in beautiful rural locations; work to control erosion or preserve wildlife in U.S. national parks; or help restore coral reefs in the Caribbean, among numerous possibilities. Animal welfare projects might center on activities like whale watching, which can include tracking different varieties of whales on the endangered species list; tracking migratory birds; or working in Asian and African elephant sanctuaries to help nurture and protect these magnificent, endangered pachyderms.

Children's causes could involve teaching English to young students abroad; working with special needs children; or assisting doctors and nurses in communities around the world that are in desperate need of basic health care. Other options might focus on cultivating sportsmanship among teenagers in places like Peru, Ghana or Argentina.

How can I get started?
Choose a project that genuinely interests you in a location you'd really like to get to know and one that matches your level of physical fitness. Be prepared to ask the organizer specific questions about the project, including information regarding appropriate clothing, gear, housing and meals. Then make lists of the items you'll need. The Internet and travel books are valuable resources that can help you research causes of interest, locations, travel options and sponsoring organizations that are actively seeking volunteers.

Andy Kessler is a writer and editor with MSN. His interests include music, the history of religions and literature.

The Ice Age Trail work party featured in this video is one of many volunteer vacations coordinated by the American Hiking Society nationwide. For a calendar of AHS volunteer