Top of the Class: In two days, Stanford University saw more than 70,000 people sign up for free online class taught by AI experts including Google celebs, Peter Norvig and Sebastian Thrun. This is hardly an accident. Thrun, who built a robot car that won a Darpa challenge and did a fine TED talk last year, says he's been inspired by Sal Khan. Thrun now works at Google in addition to Stanford. Our bet: he's brewing an idea for a company, maybe something like Khan-goes-to-college. Money quote from Thrun to the NYTimes: "The vision is: change the world by bringing education to places that can't be reached today." It will be well worth taking notes in this class.