I designed and posted a couple of T-shirts via Zazzle. I designed them to show my love for PhET. Yes, I am a geek. (Further evidence of my geeky PhET affection was provided previously on The Blog of Phyz.)
PhET is The University of Colorado's Physics Education Technology program. They design, produce, maintain, and promote high-quality interactive science simulations. And they give the simulations away for free!
I bought a black tee to wear during our PhET days (between the last of the new content lessons and the beginning of final exams). The black PhET tee looks better than Zazzle's "model display" of it. (Click the shirt to get to its product page, then click the design tab to see a better rendering.)
I've got a copy of the Matrix design ordered.
Zazzle incorporates a royalties structure so product designers can share in the revenues. I'm donating anything the PhET products generate to PhET. Seems fair.
So go buy yourself a PhET shirt! You know you love PhET, you'll be the only one in your neighborhood with one, and it supports the PhET program.