I say "po-ta-toe", you say "po-tah...
Yeah, whatever. My mom shoots potatoes a couple of hundred yards out of her potato bazooka.
Sometime in the last few years, one of my parent's friends (they have cool friends) decided that my parents could really use a potato gun. So they made one and gave it to them.
It is a rather simple device. A long piece of 2" or so PVC pipe that is attached to a short section of 4" PVC pipe that acts as the ignition chamber. The end of the 4" section is threaded for a screw-on cap and has an igniter mounted throw the side of that section.
Use is rather simple. Take a potato that is slightly larger in diameter than the long firing tube and ram it into said tube. Take a stick and push the potato down to just above the firing chamber. Unscrew the bottom of the firing chamber and blast about 5 seconds worth of hairspray into the chamber. Screw the bottom back on.
The damned thing will shoot a potato a couple of hundred yards. Over the pond and through the woods, in our case. If you aim it at the pond, the spud will skip across the surface a couple of times. Hit a tree and you get a rain of mashed potatoes.