I've done a few t-shirt designs, and they are shown below.
First, the Urban Outfitters TXT TEE. I won a slogan contest and they let me design it as well, and they were really really nice about everything and threw my URL around and it was great.
Second, a t-shirt design for UMBC Chess Week, which can also be seen under "Projects."
Last, a t-shirt design I drew on a tourbus in Israel. I went on a group trip with my best friends and some other university students and at the end they printed up some shirts for us.
URBN TXT TEE
UMBC Chess Week 2008 T-Shirt
Bus 727 T-Shirt
Drawing the Bus 727 shirt