i love webcomic shirts. they don't appear particularly nerdy to random people you meet, but they'll identify you to other internet people, and you get to support the authors of indie web comics. it's win-win-win.

examples: http://www.topatoco.com/merchant.mvc?Screen=PROD&Store_C...

http://smbc.myshopify.com/collections/shirts/products/the-mo...