Kiva was actually part of Adam's inspiration!
http://www.fastcoexist.com/1680490/making-medical-care-affor...
Members of the Watsi team work for Kiva too (at least as of several months ago): http://news.ycombinator.com/item?id=4424745
Members of the Watsi team work for Kiva too (at least as of several months ago): http://news.ycombinator.com/item?id=4424745
Of course, the nice thing about Kiva is that it is a loan, rather than a donation, which allows you to use the same initial investment to help lots of people again and again.