Backroads – bicycling, walking, and multisport tours worldwide.
EarthFoot – lists small-scale, low-impact, locally produced ecotours.
Planeta.com – a clearinghouse for practical ecotourism around the globe. Home of the Financing Sustainable Tourism Conference.
worldsurface.com – sustainable tourism for backpackers and independent travelers. Live diaries, travel guides, flight and accommodations reservation.