Tim and Chelsea get the award for "most unique birthday gift given." They got me a Beer Belly. If you're unfamiliar with the product, it's sort of a CamelBack that goes around your stomach. The idea is you put it under your shirt, fill it with beer, and sneak cheap drinks into sporting events. It just looks like you have a beer belly.
I gave it a shot today and it worked really well. We decided that for actual use in stadiums, it would be best to wear a sweatshirt over it instead of just a t-shirt. But all in all, it's pretty hilarious.
[Update] Thanks to BrooksL for posting my picture on the official Beer Belly blog!