Horseback riding in Australia, animal trekking in Africa, I could go on, and on. A great site. Has comprehensive information on adventure travel for women, the disabled, families and gay and lesbians. Traveling to more than 48 countries, Contiki has more 100 tours ranging from 3 to 52 days. Many of them undertaken in non-adventurous luxury transport.
Most tours have good, well detailed online itineraries.
However the all American male, and female, can plan their next sortie up the north face of unpronounceable mountains in the Himalayas, avoid Bilharzia in Botswana or scale a few canyons in Mexico. More of a general magazine site, but has many links to travel opportunities. Serious Adventure Sports and Outdoors Directory - Don't try any of the activities you see on this site at home, unless of course home is a 1000 square miles of the Rockies. As the name implies this site deals only in seriously mad activities for like minded people. Lots of land and water based stuff here too, from cattle driving, to the relatively gentle pastime of white water rafting.