10. Bill Gates
Source: Microsoft, self-made
Residence: Medina, WA
Country of citizenship: United States
Education: Dropout, Harvard University
Marital Status: Married
Selling charity raffle tickets is hard; coaxing tycoons to pledge half their fortunes to philanthropy is near impossible. Apparently no one told Gates. This year the Microsoft mogul, futurist and America's richest person strong-armed (with help from henchman Warren Buffett) 40 of the world's wealthiest to sign his "Giving Pledge," promising to donate the majority of their wealth to charity during their lifetimes. No longer the planet's richest person, but that's because he's given nearly $30 billion philanthropically. World's most influential charity tackles AIDS, tuberculosis, polio and funds famine-resistant crops to fight hunger. Worth $54 billion, Gates holds 70% of his wealth in investment fund Cascade, dabbling in everything from autos to hedge funds to trash collecting.
(Krista Kennell/Sipa Press/Newscom)