Thirty US billionaires pledge to give away half their fortunes to charity
Bill Gates's and Warren Buffett's campaign draws in top names including George Lucas and Michael Bloomberg
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The world of philanthropy got a huge financial boost today as more than 30 American billionaires pledged to give away at least half of their fortunes to charitable causes, signing up to a campaign launched byWarren Buffett and Bill Gates.
In an unprecedented mass commitment, top figures including New York's mayor Michael Bloomberg, the hotel heir Barron Hilton, CNN media mogu