Super-cheap program idea: The Tumblewing.

From Smithsonian's Air & Space Magazine:

This paper airplane—the Tumblewing—is a type a walkalong glider. The authors note that it’s designed to fall steadily forward and down, in a spiral. If you walk too fast, the Tumblewing will fly over your shoulder; if you walk too slowly, it will fall to the ground. So flying it takes a bit of practice. Would Orville and Wilbur have headed back to the bicycle shack if their first attempt failed?!? No!

VERDICT: It took us a couple of practice sessions to get the hang of the Tumblewing. Our first attempt fizzled because we used the wrong size cardboard. (Also, our boss told us to get back to work.) With the correct size cardboard, it was much easier to keep the Tumblewing aloft, and keeping it in sustained flight was just a matter of practicing.