[pedant]
As for the “jet” idea, it is, indeed, a jet in many senses of the word; it is just not a high temperature turbine. Jet skis operate under similar mechanisms (internal combustion engine turning an impeller pump which directs a high speed discharge of water-the “jet”) as this “jet pack.” Strictly speaking, a “jet” is not a type of engine, but the mode of propulsion. A helicopter may be, for example, powered by a turbine engine (turboshaft), but it is not a “jet powered” helicopter. Most modern aircraft are turbofan powered. A “jet,” in your sense, includes anything which is turbine powered, rather than “jet propelled.” A modern high performance hydroplane is “turbine powered” and not “jet powered,” similarly, many older aircraft had turboprop engines which did little (usually, nothing) in the way of providing a “jet” of air for propulsion. A non-afterburning high-bypass turbofan has more in common with a ducted fan lift system than it has in common with a turboshaft engine. (it produces highly directional thrust as exhaust rather than developing torque to power a separate drive system)
[/pedant]

Very similar to the Solotrek of a decade or so ago. It had a few successful tethered flights before the funding ran out.

http://www.google.com/search?q=solotrek+xfv

I bet shipping from NZ is not cheap.