Robert Scoble, in an effort to keep up with other round-the-clock walking videocasters, has strapped a camera to his head so we can witness every minute of a famed podcaster's fascinating life. But the former Microsoft evangelist looks less like Justin, the vaguely cool San Francisco exhibitionist who began the current fad for streaming self-exposure, and more like the dorky PC Guy played by John Hodgman in Apple's mocking commercials.