Separated at Birth

Are Jesse Eisenberg and Michael Cera the same person? Can anyone tell them apart? Have they been seen in different places on the same date and at the same time? I don't think so. How many earnest geeky blond 20ish boy-men do we need? Have only seen the trailer for The Social Network but it has that frenzied every single thing is of paramount importance feel that belongs to the Twitter/Text Messaging/Tell All crop of self-important peeps who will probably fall into open manhole covers while retrieving a critical message such as "on the way to the dentist."