Gates still richest in U.S. - Facebook's Zuckerberg surprises

No surprise here: Bill Gates is the richest man in the United States. However, some may be surprised that Facebook CEO Mark Zuckerberg has overtaken Apple CEO Steve Jobs on Forbes list of the 400 richest people in America.

Gates, the co-founder and former CEO of Microsoft, topped the list--again--with an estimated wealth valuation of $54 billion. Second on the list was Berkshire Hathaway CEO and Gates pal Warren Buffett with $45 billion. Rounding out the top three was Oracle CEO Larry Ellison with $27 billion.

The intrigue comes much lower on the list, where Zuckerberg, who didn't even qualify as a billionaire last year, ranked higher than Jobs, who founded Apple some eight years before Zuckerberg was even born. Ranked at No. 35, Zuckerberg ($6.9 billion) got a boost last year from a $200 million infusion of cash in his social-networking titan. Despite Apple recently passing Microsoft in valuation, the majority of Jobs' (No. 42; $6.1 billion) net worth comes from his shares in Disney, which bought his Pixar animation studio in 2006 for $7.4 billion.

For more on this story, read Gates still richest in U.S.; Zuckerberg tops Jobs on CNET News.