This fantastic record player exploded view t-shirt is available for $22.50 from ShanaLogic, who of course is also a beloved sponsor of the site you are currently reading. (But this post isn't at her urging -- I just dig the design.) "Vinyl Turntable Explosion Diagram T-shirt"
If you're headed to Las Vegas for DEFCON this summer, you're one of the lucky few who'll be able to get one of the Electronic Frontier Foundation's limited-edition, glow-in-the-dark "Encryption Saves" tees, only available to people who join the organization at the event. I won't be there this year (sob!) but I will be in 2012, where I'll be delivering a keynote. Can't wait!