A new isometric t-shirt design challenge will open soon at Threadless.
Note that this isn't a pixel-art challenge specifically. Also don't take 'isometric' too literally, Threadless isn't too strict about challenge rules. However, do take the time to think hard about what makes a good shirt design, as opposed to a good piece of stand-alone art. Would you wear it? Does it have the Threadless feel, whatever that is?
The challenge opens later this week, and should last for 2 more weeks. Go for it!