I poked around at Cafe Press for a couple hours one night about four years ago and then gave it up for lack of time, and because my lack of artistic talent was woefully obvious. If you view the magnified versions you'll see the resolution is horrible, particularly the name "EvC Forum" itself that appears in gold.
I had no idea that what I'd done was publicly accessible. If any have been sold, I'm not aware of it.
Challenge for anyone interested: if you've got the time and the talent, I can give you access to the EvC Forum area of Cafe Press and you can design some decent T-shirts and coffee cups.