Treadless!  This is where I kinda cut my teeth as a t-shirt designer.  Back in 2005, I found out about this cool website where you could go and enter a perpetual t-shirt contest.  You would upload your design and it would stay up for one week for people to vote on it and comment on it and at the end of the week, if it had enough interest and high scores, they would print it.  You would win some money and free shirts and it was fun.

I had some pretty good success at the site early on and it was a major confidence boost and popularity rush.  I went on from there to create tons of shirts for a variety of companies.