Lol..
I was just browsing through my phone trying to figure out how to edit the "LockDockBar" and find it at least, when I came across this file called "call_history.db"(/private/var/mobile/Library/CallHistory).
Opened it with TextEdit(I'm on a Mac), then went all of the way to the bottom to the most recent calls.
It just so happened someone called me private tonight on some weird BS.
You won't be able to recognize it unless the number has a *67 in front of the number instead of a #1
Hope this helps find out who is playing on your phone, and expose those that need a life instead of prank calling people.