In 3 Days Novemeber 26th you will be able to purchase Fallout 3 Avatar Items on the Xbox Marketplace if you are so inclined.
Vault 101 Suit - 240 MS POints
Bethesda Studios Shirt - 80 MS Points
Fallout 3 Ringer Shirt - 80 MS Points
Vault Boy Shirt - 80 MS Points
Vault Boy Suit - 240 MS Points
Vault Boy Head (Scary) 80 MS Points
Bethesda notes that all items can be purchased for male and female avatars, with the exception of the Vault Boy Suit. That means no boobs on the vault boy, you wanna be cross dressing freaks out there....