Apple CEO Tim Cook is joining the roster of the very rich who are giving away their wealth. Fortune magazine cited the head of the world's largest technology corporation as saying he planned to donate his estimated $785 million fortune to charity - after paying for his 10-year-old nephew's college education. "You want to be the pebble in the pond that creates the ripples for change," Cook told the magazine. The 54-year-old's revelation is an example of the increasingly public philanthropy of the world's richest people. REUTERS/Lucy Nicholson
Billionaire financier Warren Buffett, Microsoft founder Bill Gates and his wife Melinda Gates are encouraging the very wealthy to give away at least half their worth in their lifetimes through the "Giving Pledge" campaign. REUTERS/Shannon Stapleton
Melinda Gates and Microsoft Chairman Bill Gates. REUTERS/Marcus Donner
Berkshire Hathaway CEO Warren Buffett. REUTERS/Rick Wilking
Jim Walton (L) and Alice Walton, part of the family that owns Walmart. REUTERS/Rick Wilking
Mark Zuckerberg, founder and CEO of Facebook, is part of The Giving Pledge. REUTERS/Adnan Abidi
Billionaire activist-investor Carl Icahn is part of The Giving Pledge. REUTERS/Brendan McDermid
Virgin Group founder Richard Branson is part of The Giving Pledge. REUTERS/Suzanne Plunkett
Sheryl Sandberg, COO of Facebook, and her husband David Goldberg, CEO of SurveyMonkey, are part of The Giving Pledge. REUTERS/Rick Wilking
Former New York City Mayor and founder and CEO of Bloomberg, Michael Bloomberg, is part of The Giving Pledge. REUTERS/Jonathan Ernst
Tesla Motors CEO Elon Musk is part of The Giving Pledge. REUTERS/Rebecca Cook
Fashion designer Diane von Furstenberg and husband Barry Charles Diller, CEO of IAC/InterActiveCorp, are part of The Giving Pledge. REUTERS/Danny Moloshok
Energy entrepreneur T. Boone Pickens is part of The Giving Pledge. REUTERS/David McNew
Media mogul Ted Turner is part of The Giving Pledge. REUTERS/Phil McCarten
Oracle co-founder and CEO Larry Ellison is part of The Giving Pledge. REUTERS/Stephen Lam
Hedge fund manager George Soros. REUTERS/Pascal Lauener
Activist investor Bill Ackman is part of The Giving Pledge. REUTERS/Brendan McDermid
Microsoft co-founder Paul Allen is part of The Giving Pledge. REUTERS/Richard Clement
Michael Dell, founder and CEO of Dell. REUTERS/Lucas Jackson