AceShowbiz - Irish rocker Bono is cashing in on the popularity of social networking website Facebook.com - the U2 frontman has nearly doubled his investment in the company. Bono and bosses at his private-equity business Elevation Partners have ploughed another $120 million into the privately-held site, bringing their total investment in Facebook to $210 million.

According to a letter to investors published by the TechCrunch blog, Elevation bosses were able to buy shares from insiders on the secondary market. The deal could be the start of an investment turnaround for the rocker, whose blunder backing troubled cellphone maker Palm Inc. won him the dishonor of being named Worst Investor in America by financial journal 24/7 Wall Street earlier this year.

Bono's company ploughed nearly $500 million into the debt-riddled firm, the maker of Treo and Centro smart phones, in December 2008, before stock shares plummeted. Editors highlighted "an unprecedented string of disastrous investments which even bad luck could not explain" as the reason for choosing Bono, adding that California-based Elevation Partners is "arguably the worst run institutional fund of any size in the United States".