As U.S. special forces assaulted Osama bin Laden's walled compound in Pakistan, a Twitter user was already recording a rough outline of the events to come. Sohaib Athar, who describes himself as a 33-year-old programmer and consultant "taking a break from the rat race by hiding in the mountains with his laptops," happened to be staying up late at the time. And, from an account called Really Virtual, he live-blogged what he heard. Athar's real-time dispatches and self-effacing follow-ups have transformed him into an instant online celebrity. He's received at least one marriage proposal--through Twitter, of course--as well as requests...