Bing Bang Boing was a genius 1970s board-game where players laid out trampolines, funnels, spirals, elevators and other apparatus and then released marbles through the run you'd built. The effect is basically Mousetrap with bouncing, and it features heavily in the kids' toys cartoons I blogged this morning.
Rob, a blogger, recreated Bing Bang Boing for his kids with balloon-and-peanut-can trampolines and other props, and has details on how he did it, along with a video of the toy in action.
(Thanks, hexmonkey!)