I have a suggestion for a contest, that would be, aside from being a contest, a collaboration.
Stage 1: Common approval of a theme. Sci-Fi, surreal, could even be multiple themes.
Stage 2: Designation of Object catagories. Each participant would be required to do a minimum of 1 object for each catagory.
Stage 3: Submission of Objects to be compiled into a single .blend file
Stage 4: Contestants Model a scene using objects from each of these catagories.
Stage 5: Vote for best scene, and best object.
So what do you think? <doing groucho marx impersonation>