Sean McMain's Amazing Pneumatic Cannon

Recently, I made a trip to our local hardware store to pick up the parts for something I'd read about on the Internet: a cannon, made of PVC pipe and a sprinkler valve, that could launch objects hundreds of feet using nothing more than compressed air. Figuring the amount of fun one could potentially have with such a thing far exceeded the paltry $25 required for the parts, I decided to give it a try...

Cool!