It was a good idea for a challenge and i wish i got it finished.

Something Ive been wanting to do is a lighting and rendering challenge. Something less realistic and more surreal.

Why not model a crystal shape or some abstract form and set the challenge of texturing, shading, lighting and rendering it in the most interesting way? That way people can go as far or as little as they want with it.

This could also be combined with THX's idea of stereo rendering (although this might bring it into the 'too hard and complex' realm)