What i'm talking about here is those funky little pistols you see in various movies (Alien Resurrection, the guy with dreadlocks is packing a pair, and in the latest Sherlocke Holmes, that guy... can't remember his name, has one) which are strapped to the users forearm(s), and with a simple wrist or arm movement a pistol slides out of the sleeve and into the users hand, then with another movement they retreat. Now i'm curious if such a device even exists outside of fiction, how it works, whether they've been used at any point in history, and if there's a web link i can use to find out more about these awesome contraptions.