SWe've always been impressed by Facebook CFO Gideon Yu's ability to snooker investors around the world. The list of people he's taken for a ride include Microsoft CEO Steve Ballmer and Hong Kong telecom mogul Li Ka-Shing. Just last Friday, he returned from a trip to Dubai, where he tried to shake loose some petrodollars from the Middle Eastern emirate's sovereign wealth funds. Some people seem to think Yu is still in Dubai. Which would be quite a feat, considering he's been spotted in Facebook's Palo Alto headquarters multiple times this week. Perhaps he's using CNN's new hologram technology?