Okay, I was NOT expecting the kind've outpouring of interest I got--I wrote that post and took a nap, fer cryin' out loud, and I came back and there were 26 entries! Holy wombats!
You people are so awesome.
A biiiiig thanks to shatterstripes for setting up the community at art_challenge and to everybody else who offered to donate codes and so forth! So! We're gonna give this a shot! Everybody just point yourself over to that aforementioned community, and I'll try to have your first art challenge up and running, in just a minute or two!