I just downloaded all the data that FB has on me. It's quite surprising to see every single message and wall post I have made and others have made to me.

One thing I realized is that even if I delete my account, facebook will still store my communication with other people in case they request to download their information too. So I'm not sure if it would ever get deleted unless both parties delete their accounts? For my info to truly get deleted, all of my contacts would have to delete their accounts too.