Hammer didn't do anything here that hadn't been done before, but the genius behind his casting was that he was not very well known (unless you had seen Gossip Girl); it was possible for many moviegoers to believe that he actually was identical twins. And, unlike most of his Social Network co-stars, the image of Hammer as Harvard rowers and Facebook-suers Cameron and Tyler Winklevoss has eclipsed the image of the actual, real-life twins.