This article has a few links but REALLY is lacking this one:

http://en.wikipedia.org/wiki/Giving_What_We_Can https://www.givingwhatwecan.org/

And interesting bunch of people where you pledge to donate X% of your pre-tax income to charity for life. The founder, Toby Ord capped his income to 18,000 British Pounds:

http://en.wikipedia.org/wiki/Toby_Ord