Comes from Dinosaur Comics for those who liked it.
Took me a while to warm up to the comics, but there's some gold in there, eg:
http://www.qwantz.com/archive/001426.html http://www.qwantz.com/archive/001433.html
Also, while I'm spouting random and totally subjective opinions about Dinosaur Comic related things, I much prefer this shirt
http://www.topatoco.com/merchant.mvc?Screen=PROD&Store_C...
to the time travel one, but maybe I'm just a big kid.