Hydrogen peroxide powered rocket packs fly for around 30 seconds, because they have a specific impulse of around 125, meaning that one pound of propellant can make 125 pound-seconds of thrust, meaning that it takes about two pounds of propellant for every second you are in the air. Mass ratios are low for anything strapped to a human, so the exponential nature of the rocket equation can be safely ignored.

A pretty hot (both literally and figuratively) bipropellant rocket could manage about twice the specific impulse, and you could carry somewhat heavier tanks, but two minutes of flight on a rocket pack is probably about the upper limit with conventional propellants.

However, an actual jet pack that used atmospheric oxygen could have an Isp ten times higher, allowing theoretical flights of fifteen minutes or so. Here, it really is a matter of technical development, since jet engines have thrust to weight ratios too low to make it practical. There is movement on this technical front, but it will still take a while.

John Carmack

Just thought I should point out that while high speed broadband (i.e. 8Mbps and faster) may not be commonly available in the US, there are plenty of other countries where it is.I'm in Australia, and we've had 8Mbps for a while now, with ADSL2+ (up to 24Mbps) being rolled out in the next year or two. Don't even get me started on what Korea and Japan have available.

My point is that there are markets outside the US ready for these types of innovations *now*, and I don't see why we should be waiting for the US to get it first.