Glove guns are surprisingly powerful and accurate weapons that work the same way as a sling-shot (or shanghai as we used to call them). The rubber is the finger of a rubber glove - hence the name. Instead of a Y shaped stick the rubber is mounted on the end of a pipe that forms the barrel of the gun. The projectile is dropped through the barrel into the finger, the finger is then stretched back and released sending the projectile down the barrel at very high speed.
Have a look at this video for a look at a basic glove gun in action using small lead fishing sinkers as ammo...
Have a look at this video to see the double barreled version using darts.
Glove guns have probably been around for as long as there have been rubber gloves and naughty boys, but I only met my first one last weekend. I was very impressed and had to make one. It ties in nicely with the Duct Tape Competition too.
I had better warn everyone that glove guns could be a very very dangerous. They could do serious damage to eyes and pretty much anything else they hit. Always be sensible and please keep the things out of reach of youngsters. Supervise children closely - as if it was an air rifle or fire arm.