Lay'emLow, Love the gas tank. I saw a pic somewhere on the internet of an motorized bicycle with a side-car made out of a full size keg. I wish I could remember where I saw that. Anyway, if you wanted to keep the keg theme going then that would be a good option, plus you could haul groceries in it.
I do have a question though. What did you use for a filler neck and gas cap on you're tank?