If you have an Xbox 360, head on over to Xbox.com's page for Final Fantasy 13 and register for their promotion there. You'll receive a baby chocobo avatar item, sometime in the future. They mentioned that they're sending out the emails with the download codes 'this holiday season', which could mean now, or next week. Who knows. I signed up for this when the Twitter campaign was still active and I don't have mine yet, so you still have a chance.
Be advised that this offer is region restricted, so make sure you visit the Xbox site relative to your location! Here are some easy links for common regions:
US :: Canada :: UK :: Australia
If you're not from any of those places, just go to Xbox.com first (it will automatically put you in the region you're supposed to be in) and then search for the game.
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