Our favorite charity-worker Bill Gates has successfully signed up 38 billionaires to give away half of their wealth to those less fortunate, in what could be the largest-scale philanthropic work ever.

Together with Warren Buffett, their "The Giving Pledge" project nabbed Larry Ellison (founder of Oracle), George Lucas, New York Mayor Michael Bloomberg and Barry Diller from IAC (an internet media company that owns Ask.com, Bloglines, Vimeo, Match.com and others), along with many others.

While they're not legally bound to give away at least 50 per cent of their wealth to charity, it's more of a trust-promise—particularly now that it's been reported all over the media. They're not expected to give their notes to any one charity, but if every single person on the Forbes 400 richest American list signed up to The Giving Pledge, that would mean charities would be $600 billion better off. Presumably some of those charities will be green-focused, considering Gates' obvious passion in that field. [WSJ]