If you live in Germany you can rent an AirKick for an undisclosed amount of bratwurst. The human catapult (not to be confused with a human trebuchet) is capable of launching thrill-seekers 26 feet to a watery landing.
The participant sits in a specially constructed seat at the back end of the catapult arm and 3,2,1...Liftoff. He sets the device in motion himself by pushing a button. Approximately 60 liters of water are then forced through a rocket nozzle under the seat.
Awesome! I'm having them send one over here for testing, I'll report back.
UPDATE: Greetings from the ER! Not for use in the mall parking lot.
Thanks Eric and Pat, but you could have warned me you know.