Don't know if anyone else here uses this (considering the complete lack of response to my other post I think that there is no one else here...), but just in-case you're interested - Raptr is a social gaming tool that allows you to connect with your gaming friends on one list (so taking into account XFire, Steam, XBoxLive, etc).

It also produces near summaries of what you've been playing and for how long (once you've set it up properly), and compares scores amongst friends.

I like it just for obsessively keeping track of how long I play each game for...

Homepage is: Raptr - there's a client that runs seamlessly in the background on the PC