I finally got around to ordering a T-shirt from Redbubble!
Redbubble is an Australian company based on the Cafepress-style business model; Creators upload their works onto the site, from which consumers can purchase prints or printed goods featuring the works. In exchange for hosting your image/profile, doing the printing and posting the item, Redbubble take a fee from the sale. It's a pretty cool concept and I'm really happy to support this sort of venture.
I decided on this design by "lowvincentyh", "lowvincentyh", available here.