At the f8 developer conference Thursday, it was revealed that Facebook now has more than 800 million monthly active users (ie, that many people have used Facebook in the last 30 days). This marks an increase of 50 million monthly active users since early July.

Meanwhile, Facebook CEO Mark Zuckerberg revealed that 500 million people used Facebook in a single day last week. That’s a powerful level of user engagement. At the July event where Facebook’s Skype-powered video calling feature was revealed, Zuck said he wanted Facebook to eventually have a billion users. I don’t think the social network will have to wait too long to hit that huge number.

Meanwhile, Zuckerberg also revealed details of Timeline, the new-look Facebook profile, at f8.