Michael Cera, in the inevitable hoodie, on left. Shia LaBeouf, in corporate neckwear, on right.

Social networking sites are atwitter in anticipation of the upcoming book, The Accidental Billionaires (to be published Tuesday) and David Fincher film, The Social Network (screenplay by Aaron Sorkin) about Facebook's founder Mark Zuckerberg. (Hat tip: A List of Things Thrown Five Minutes Ago).

The two names bruited about to play the shaggy and shifty Zuckerberg, the socially-challenged guy sued by his partners, are Michael Cera (Arrested Development, Juno, Year One) and Shia LaBeouf (Transformers, Disturbia, Indiana Jones XXXVI). These gifted young actors share offbeat timing and self-deprecating humor but little else. Cera is an Indieworld darling (see Juno, Nick and Norah's Infinite Playlist, the upcoming Paper Heart) while LaBeouf  has been anointed Bankable Hollywood Youngling. I like them both, but if I was casting this movie I'd go with Cera, who would be a bigger surprise as the guy who sells out his partners, than LaBeouf, so eager for bigtime success that it would not be a surprise if he elbowed the competition to get to the finish line. (Not that it matters, but Cera more resembles Zuckerberg.) In other words, Cera plays loveable losers, LaBeouf eyes-on-the-prize winners. It's like the difference between Matt Dillon and Tom Cruise.

Your thoughts? Favorite Cera and LaBeouf roles.