From Xbox.com:

If you’re an Xbox LIVE Gold member, and you want a chance to play with Tenacious D, send a friend request to the following Gamertags and be online half an hour before (8:00 P.M.) the Game with Fame session starts on Thursday, November 20, 8:30 P.M. ET.

• JBTenacious
• KGTenacious

I always liked Tenacious D, and this promotion only makes me like them more.  Hopefully you’re lucky enough to play with Jack or Kyle tonight!  What’s your favorite posish?  That’s cool with me, it’s not my favorite but I’ll do it for you.