T-shirts from the craft store and markers are cheaper. Unfortunately I didn't have a real camera to take this with; had to hold it up in front of the webcam and so some of the letters are covered by folds.
I am considering what to write on the back; the Fourth Amendment was a possibility, but this marker is starting to run dry, so I'm not sure.
Edit: Did not write anything on the back, wore it through PIT today. The Southwest check-in people seemed to get a kick out of it; TSOs didn't seem to notice. I figure they probably see worse.