Forty American billionaires have made moral (i.e. not binding, but public) pledges, at the urging of Bill Gates and Warren Buffett, to give half their fortunes to charity, instead of using them soley to spoil future generations. Among those taking the pledge plunge: Paul Allen, Mike Bloomberg, Eli and Edythe Broad, Barry Diller and Diane von Furstenberg, Larry Ellison, Barron Hilton, Ken Langone, George Lucas, Ronald O. Perelman, Pete Peterson, T. Boone Pickens, David Rockefeller, Ted Turner, Sandy Weill and Shelby White. Visit to see the entire list — and if you’ve got the money, join in.