Just for kicks, I've launched a T-shirt store. It's called T-shirts by My Future Past, at CafePress. I make up the designs in Photoshop, then CafePress prints them one at a time. Anyone can order - I'd be honored and amused to meet one of my shirts on the street! The one I posted a picture of recently is there, along with a worksafe version.
Here's one for the environmentalist in you:I say it's just for fun because I'm not making any profit on them. CafePress allows designers to mark up their products and earn money, but I haven't done that. The prices are whatever CafePress charges for the shirt - organic cotton costs more, for example. And they'll only let me use each type of shirt once ("dark men's fitted T-shirt" or whatever) so there's a large range of prices. If you'd like a design printed on a particular type of shirt, let me know; I can make that shirt available by temporarily taking down another design.
Here's another alcohol-themed one: