If you have a http://www.mycokerewards.com account, and you’ve put in 6 bottle-cap codes recently, try logging in and typing “football” as a code. It will trigger a free college football t-shirt.
If not, then if you have 6 codes, put them in, and then try the ‘football’ code as your 7th. 🙂
They have several to choose from in several different sizes.