This is now the third trailer to be released for The Social Network and up to now, we’ve not actually seen any footage from David Fincher’s movie (first here, second here)…… Hooray for the full theatrical trailer which has been released today over on Yahoo.

The Social Network is based on the book, The Accidental Billionaires: The Founding of Facebook, a Tale of Sex, Money, Genius and Betrayal by Ben Mezrich (author of Bringing Down the House which was then turned into 21) and it should be with us some time in 2010. It stars Jesse Eisenberg, Justin Timberlake, Andrew Garfield, Joseph Mazzello and Armie Hammer.

Yahoo also give us a synopsis: On a fall night in 2003, Harvard undergrad and computer programming genius Mark Zuckerberg sits down at his computer and heatedly begins working on a new idea. In a fury of blogging and programming, what begins in his dorm room soon becomes a global social network and a revolution in communication. A mere six years and 500 million friends later, Mark Zuckerberg is the youngest billionaire in history, but for this entrepreneur, success leads to both personal and legal complications.

Check out the trailer below for the movie which is due to be with us towards the end of the year (we think!).