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
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