Volunteering opportunities abound in the eastern USA, providing a memorable chance to interact with locals and the land in ways you never would when just passing through.

Casual, drop-in volunteer work is plentiful in the big cities. Check weekly alternative newspapers for calendar listings or browse the free classified ads online at Craigslist (www.craigslist.org). The public website United We Serve (www.serve.gov) and private websites Idealist (www.idealist.org) and VolunteerMatch (www.volunteermatch.org) offer free searchable databases of short- and long-term volunteer opportunities nationwide.

More formal volunteer programs, especially those designed for international travelers, typically charge a fee of $250 to $1000, depending on the length of the program and what amenities are included (eg housing, meals). None cover travel expenses.

Green Project (www.thegreenproject.org) Working to improve battered communities in New Orleans in sustainable, green ways.

Habitat for Humanity (www.habitat.org) Focuses on building affordable housing for those in need.

Sierra Club (www.sierraclub.org) 'Volunteer vacations' restore wilderness areas and maintain trails, including in national parks and nature preserves.

Volunteers for Peace (www.vfp.org) Grassroots, multiweek volunteer projects emphasize manual labor and international exchange.

Wilderness Volunteers (www.wildernessvolunteers.org) Week-long trips helping maintain national parklands and outdoor recreation areas.

World Wide Opportunities on Organic Farms USA (www.wwoofusa.org) Represents more than 2000 organic farms in all 50 states that host volunteer workers in exchange for meals and accommodations, with opportunities for both short- and long-term stays.