Sometimes I think the best craft project is the easiest. When my son was little, I used to give him a one-time use camera and let him go. While the resulting film was eccentric (close-ups of furniture and the dirty laundry in the hamper, yay) sometimes you can find hints of expected genius in a kid's unspoiled view of the world.
With digital cameras, it's even easier to to let them click away with the camera. The good ones can be printed out and mounted on foam core board for instant wall art.