To coincide with the launch of their new Personal Factory 4 services, Google SketchUp is announcing the Ponoko 3D Printing Challenge. Basically, the challenge is to produce a piece of instructional content that’s equal parts enlightening and entertaining. Each entry must be titled “How to use Google SketchUp for Ponoko 3D printing,” but aside from that, the format is pretty open. Text, images and video (or some combination of the three) are all fair game.