Secret Origin of the Batsignal T-Shirt
Summoning Batman to the roof of the Gotham City Police Department is a dirty job, but somebody's gotta do it. Honor the sacrifices of generations of lethargic bats in this t-shirt design from Threadless Tees. (Available for both men and women)
Or if you have $300 lying around, you could just buy your own batsignal.