During my first semester at Georgia Tech, I discovered Shirt.Woot and their awesome design derbies. Every week they come up with a theme and ask for submissions. The submissions get voted on by Woot users, and the top three shirts are made and sold at the end of the week. I entered the contest a number of times, placing in the top 20 more than once. Here are some of my favorite ones:
uprooted_by_link42
urban_equalizer_by_link42
an_apple_a_day_by_link42
You rock!