After 13 years on top, Bill Gates is no longer the richest man in the world. That honor now belongs to his friend and sometimes bridge partner Warren Buffett. Riding the surging price of Berkshire Hathaway stock, Buffett has seen his fortune swell to an estimated $62 billion, up $10 billion from a year ago. Gates is now worth $58 billion and is ranked third richest in the world. He is up $2 billion from a year ago, but would have been as rich--or richer--than Buffett, had Microsoft not made an unsolicited bid for Yahoo! at the beginning of February. Mexican telecom mogul Carlos Slim Helú now ranks as the world's second richest person with a net worth of $60 billion.