Facebook announced tonight that this week it will hit the 400 million user milestone - an incredible milestone. Just last year they were serving less than 200 million and now it's doubled. Not to mention, today is Facebook's 6th birthday. That's right, it was founded on February 4, 2004.

Also, click here for updates on the new redesign, which 80 million users will be receiving TONIGHT; the rest of you will get it very soon through the slow roll out across the now 400 million users.

Bravo, Facebook, bravo.