Bell Aerosystems developed this nifty hydrogen peroxide-powered “Bell Rocket Belt” for the US military in the 1960s. See it in action after the jump.
This jetpack’s propulsion works with superheated water vapour. A gas cylinder contains nitrogen gas, and two cylinders containing highly concentrated hydrogen peroxide. The nitrogen presses the hydrogen peroxide onto a catalyst, which decomposes the hydrogen peroxide into a mixture of superheated steam and oxygen with a temperature of c. 740 °C