Use Your Gamer Launch Account
Your account from any Gamer Launch site is valid here.
If you already have a Gamer Launch account connect your Facebook account on your user profile first before using Facebook connect to login. Otherwise you may end up with a new account.
Xexer asked me for some gold... so I told him I would give him 3000 pieces. I just forgot (conveniently) to hit accept... and stood there for ten minutes to see what his reaction would be.