Professor Ernesto Slickvom's Horizontal Sapient Projectile Launcher

You are greeted by the kindly, but obviously mentally bent Professor who is wearing a visibly blood stained lab coat. A man is standing behind him holding a strait jacket and a large net, in case things get out of hand. The good Professor first gives you an antique leather flying helmet with goggles and fits you with a body harness. There are bungey cords attached at the hips. You sit at one end of a tremendous slip and slide, which would have to be at least a couple of hundred feet long. It's covered with a film of water. At the midpoint of the slip & slide are stout anchor mounts to which are attached the other ends of the bungey cords. The cords are, of course, pulled very tight. Yes, you are the BB in the wrist rocket. The Professor laughs maniacally, perhaps hoisting a dry ice laden drink to toast your upcoming doom and pulls a large, creaky release lever which lets you go hurtling down the slip & slide. You pass the center point and at the other end, you start stretching the cords, which whip you back and forth several times before running out of steam. A lab assistant retrieves you, releases you from the harness, congratulates you on surviving the experiment and thanks you for your participation. A midget with a Peter Lorre accent accosts you and tries to sell you a fright photo taken one second after launch.