"At Forbes we spend a lot of time calculating the billions that people have amassed. We also track what they give away. Based on our recent analysis, we have identified what looks like a pretty elite club: 19 people who have already donated at least $1 billion each to charities or foundations. That is five more than we found two years ago. More than two-thirds of these philanthropists (13 to be exact) are from the U.S. and all but one is a self-made entrepreneur.
To read the entire article, go to Forbes - http://blogs.forbes.com/luisakroll/2011/05/19/the-worlds-biggest-givers/