Steven Sinofsky, President of the Windows and Windows Live Division at Microsoft, has turned his Surface tablet into a skateboard. Mr. Sinofsky turned mounted skateboard wheels on the tablet and rode it through the lobby of Studio B, which is the home of the Surface tablet. ?Couldn?t resist taking it out for a spin,? said Sinofsky on Twitter. He also borrowed a helmet from a colleague. The 10.6-inch screen made it easy for him to balance on the tablet-skateboard. This past week Microsoft announced that the Surface tablet will sell for $499 and up.