If you're an Xbox Live Gold member, and you want a chance to play with Kerli all you need to do is send a friend request and then be online half an hour before the session starts.
Xbox Live Game With Fame featuring Kerli
Date: Thursday, November 20, 2008Time: 5:00 P.M. - 7:00 P.M. ET/2:00 P.M. - 4:00 P.M. PT
Game: Quantum of Solace
Gamertag: KerliGWF
You can score more info on the event here.
