Custom clipart???? That lets me out. I don't have a creative bone in my body!!
I think it would certainly be fun to watch the contestants go at it. Better wait until BT returns, though. I'd think she would be interested in getting in on this.
Don't know what you might have in mind for rules. I'll throw out some suggestions.
1. Must post all entries to a competition thread.
2. Have a start and end time for posting to the thread. (1, 3, 7 days or some defined time)
3. Contestants are on their honor to not use clipart created prior to the start time. (can use "ideas" from other work they've done previously)
4. Must define custom (how much content from downloaded art and how much "custom")
5. At the end of the time, each contestant would select some defined number of clips from those that they had posted on the competition thread and move them to another thread to be judged. Each entrant gets the same number of entries. They must be pulled from the original thread without modification.
Just some thoughts.