Hey I'm on another forum that found this.
Basically go to here:
https://www.facebook.com/xboxie?sk=app_176445459127333
Like that page, and then enter your gamertag at the bottom (NOTE THIS WILL NOT WORK IF YOU ALREADY HAVE A GOLD SUBSCRIPTION!) However, and that is a big however. You can be imaginative and use random words and eventually find one that works. For ex. My GT is HydroThunder 2 So I tried HydroThunder 1. But I was successful.
You can try these as well.
http://www.digitpress.com/forum/show...pdated-9-11-10)
Enjoy.