Following a recent Twitter publicity promotion, Microsoft have now declared a free Xbox LIVE Avatar item for Final Fantasy XIII has been unlocked!

 
‘Final Fantasy fans banded together via Twitter, sending thousands of messages. Your Tweets, heard loud and clear, have revealed the exclusive Xbox LIVE Chocobo avatar award.’

Anyway in order to receive the code to unlock a Chocobo one must register here: http://www.xbox.com/en-GB/games/splash/f/finalfantasyXIII/

 
Codes will be sent out in December. Good times.