William Gurstelle, a contributing editor at MAKE, has produced a series of project posters, measuring 36" x 24". The first two in the series are available on his web site, Ballisticom.
Potato Cannon: This device fires a potato at speeds approaching 100 mph. The poster includes information on a variety of ignition options including taser, piezo, and flint/steel systems. Clear and concise directions; outstanding performance!
Flamethrower: Technically, this is a propane cannon, as it uses commonly available propane as opposed to the much more dangerous type using gasoline or kerosene. Complete information including key parts and supplies, dimensions, safe operating instructions, and more.