If you thought rotary tools like the Dremel were all work and no play, Make has a fun tutorial you'll definitely want to try. You'll need access to a 3D printer to create this flying toy disc affectionately called the Dremel Devil, and a rotary tool that you can power outside where it's safest to try this out.
If your rotary tool can hit speeds of up to 30,000 revolutions per minute you can actually launch the Dremel Devil a good 60m. But remember, even at low speeds this definitely isn't an indoor toy, unless you can also use that 3D printer to replace light fixtures, lamps and anything else this hits while bouncing around a room. [Make]