I posted some time ago about my mission of creating a bunch of old-school RPG inspired T-shirts. I've been gleefully wearing my AD&D Players Handbook T-shirt since then, but the concept kind of sputtered out after the printing place told me that the dungeon map I'd prepared for my next effort was no way printable on a T-shirt. Too many complex little twisty bits, apparently. So I could have gone back to the drawing board and re-worked something much simpler, but I was kind of disheartened and gave up.
However, my girlfriend recently gave me this -- she'd secretly taken a dungeon map I was working on and turned it into a T-shirt! Amazing! I have been wearing it with geek pride :)
The interesting point came up that most "normal people" (i.e. non-gamers) probably have no idea what the image on the shirt is, and indeed have no concept of what a dungeon is, poor fools!
ps. To players in my Labyrinth Lord game: maybe don't study this image too closely, as your characters will probably find themselves in this dungeon at some point, and we wouldn't want to spoil all the surprises would we! ;)