Or something completely different?
The contest for the next month will be our moving parts contest. It will start today and run until the last day of March. To enter into the contest upload a model and add movingpart as a tag. Community votes will decide the winner. The winner will recieve $300 in 3d Printing from us. We have a blog post here that shows you some moving parts that have already been made with 3D printing. We also have a mini-tutorial here that shows you how to make some basic moving parts.
We would suggest that you guys design for White, Strong & Flexible since it enables you to have wall thicknesses of 2mm(or less 1mm but only make a small portion of your model this thickness), since the support material for it is a powder it also allows for better clearances and thinner parts. Another reason to use WSF is that it is flexible so you could do things with that also. Good luck!