Canoflauge can covers are made out of vinyl and printed to look like soda cans. You just wrap one around a cold beer, and presto, time to drink in public. I think they could have done a little better with the names, but whatever, you'll have your hand around it anyways. The (reusable) set of four costs $5.89. Mine arrived this morning, so I'll take a stroll around town and let you know how they work.
UPDATE: I was out of beer so I just stuck two of them on a bottle of Jagermeister. It wasn't very convincing, a cop on a Segway arrested me. Someone please post bail. No rush though, I think my cell-mate is a personal trainer and we're going to do some exercising. Great guy, said he's really gonna give my ass a workout.
Canoflauge: This Isn't Beer Officer, It's a Refreshing Can of Skunkpiss [gizmodo]
Thanks to Bianca, who has one of my favorite names, for the tip