This is a trampoline i made in the latest 1.8 snapshot, 14w18a. It automacilly make you bounce, and you can also choose a "Skyfall" mode, which teleports you up to the sky, and let you fall down again for an ultimate jump. Also, dont care about the fact that the redstone dusts is pointing in wrong direction, its a bug, but it still works as usual. Enjoy ;)

Note that later, I will possibly create a new version of it, as the feature to push 11+ blocks with multiple dispensers is possible.

Requires snapshot 14w18a or newer.