Facebook has just announced that its third “f8″ developer conference has been scheduled for April 21-22 in San Francisco. No venue has been announced yet, but it’s the first time the event will officially take place over two days.

f8 is a great way for developers to connect and those interested in the Facebook ecosystem to learn more about what’s happening. Facebook has also used the event to make major announcements in the past. Facebook initially announced the Facebook Platform at the first f8 in May of 2007. In July 2008, it announced Facebook Connect. Facebook didn’t hold an event in 2009, instead opting for a larger event in 2010.

f8 2010 could see more announcements around Facebook’s Credits virtual currency, which the company has been gradually rolling out to developers to power virtual goods purchases in Facebook apps and games, identity and the “Open Graph” API, which Facebook has only discussed briefly, or mobile, where Facebook has been growing by leaps and bounds.

Check out the f8 Facebook Page here. We’ll be there in full force, and look forward to meeting more of you in April!