Kaioo

kaioo is a non-profit social network website that started in November 2007 as a beta version in English and German. kaioo offers its users standard features of social networking websites. They can create profiles, communicate with friends, join groups, upload pictures, etc.
The unique feature of kaioo is that all advertising revenues are donated to charities. Users can form and join groups favoring specific charities, and the ten charities with the largest groups receive donations at the end of the year, proportional to their support among the kaioo users. The operating costs of the sites are covered by donors.

http://www.kaioo.com