The first site that came to mind when I read this was I'm In Like With You. They make you profile say things like the "15 year old girl" thing you mentioned. - Kevin Bondelli from FriendFeed MT Plugin

There are two issues that come to mind when its about filling out profiles: 1) the user must WANT to complete the profile (regardless of how "fun" the process is; 2) the user must TRUST the site with the information in the profile. Its very interesting to see profile complete rates change simply by the fields requested, and where the profile itself is placed in the signup process. - Micah Baldwin from FriendFeed MT Plugin