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

How did this obvious troll get modded up to 5?

No business pays people to read email all day. There are dozens of good free and commercial spam filters. Even when you set the software to be very sensitive to false positives, you have still filtered away almost all of the spam. The only things that get through here are strangely worded Nigerian email scams, which confuse the Bayesian filter.

Unless your customers are constantly complaining that:

• their cocks aren't getting bigger
• their horse-loving-farm-girls aren't really "barely eighteen"
• they are still not multi-millionaires after 20 hours working at home

then you are talking out of your ass about sifting through thousands of emails a day.