I know Threadless will take submissions for new designs frequently, and they cater somewhat to the "geek" demographic. It may not be entirely what you're looking for, but perhaps worth a shot. 
__________________
"The world is so exquisite with so much love and moral depth, that there is no reason to deceive ourselves with pretty stories for which there’s little good evidence. Far better it seems to me, in our vulnerability, is to look death in the eye and to be grateful every day for the brief but magnificent opportunity that life provides"
-Carl Sagan
|