I found this website (www.cafepress.com) that allows you to upload images and put them on shirts, hats, and stuff. Then you can order the shirt you made. You can open a free account.
For fun, I made up this shirt. It's a picture of the heads of the guys I work with in the IT department. Then, underneath it, it says "These guys are a bunch of freak'n Girls."
Click on the shirt to make view larger.