Molly Goatwax has some excellent T-shirts up for sale for 15 bucks. I've already got mine.
Molly won my heart forever when I came across her blog and saw she'd made a triptych that serves as a weather station, bottle opener, and tribute to a Baltimore Sun columnist. Form, function, barometric pressure.... I was in awe. Even if you don't want to buy a shirt, go on over to her site and look at them because they're cool.