It's time for Comic Con; that special time of year when thousands of nerds invade southern California in the name of all things, sci-fi, action and of course, comic books.  Making a stop at this year's convention were Guy Ritchie and Gerard Butler with their new movie RocknRolla. Like the rest of Ritchie's films RocknRolla is set in the London underworld when a stolen painting pits some of  the city's scrappiest tough guys (Butler) against its more established players.  Check out the trailer here and look for RocknRolla in movie theaters this fall.