There is quite a bit here. I've had this one the longest: CafePress - tees, mugs, prints and more!
Color t-shirts available here: Zazzle - shirts. I am in the process of adding the same stuff as my CafePress shop!
Not much here due to their weird requirements, but they are really cheap prints: Deviant Art Prints - photo paper.
I also make prints at home and buttons. E-mail me with any requests! :) (email address below)