Ever since he retired, gave up his throne and handed the scepter to Steve Ballmer, people have been wondering what Bill Gates is up to. Old news says Bill is hangin' out in his new office, designing logos for whatever his next company might be. New news says he patenting random things and this week, it's cars. Last week a patent filed with the U.S. Patent & Trademark Office in 2007 and detailing an electromagnetic engine was made available for public viewing. Among the ten inventors listed in the patent--as well as Searete LLC, part of Intellectual Ventures--is none other than Mr. Windows himself, William H. Gates, III, and Microsoft's former chief technology officer, Nathan Myhrvold. As you read on, the patent starts throwing around words like particle beam igniter and plasma injector. Seriously. Hit up the original post for diagrams and the full story.