Bill Gates is once again the richest man in the US, with a net worth of $57-billion.

Warren Buffet, who briefly displaced Gates at the top of the list last year, is behind him with a diminished wealth of just $50-billion.
The Forbes list of the US's richest people is littered with IT moguls, with Oracle's Lawrence (Larry) Ellison coming in at number three.
Michael Dell, founder of Dell, is at number 11, followed by Microsoft's Paul Allen at number 12 and Google's Sergey Brin at number 13.