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

Are they going to tax internet video conferencing and Netmeeting next? Instant messaging?

Quiet, please. Let's not give them any ideas.

For antitrust purposes, a monopoly doesn't mean what most people think it means. Antitrust is about behavior, not about size.

As my antitrust professor used to say, owning the only movie theater in town may be a monopoly by the dictionary definition, but it isn't an antitrust violation. Being one of two movie theaters, then buying the other one and closing it down, is.

There have been reported antitrust cases where a company actually controlled only 5-10% of the market-- but used that 5-10% to fix prices, block access to the market for new companies, or attain control of a supply chain to eliminate competitors. (I've often wondered whether Apple could get into serious antitrust trouble for supplying Apple Stores with Hot New Items faster than they do independent Apple dealers) Recall that the big issue in the DR-DOS suit involved Microsoft modifying Windows to detect DR-DOS and then not run.

Microsoft may not have the market share that it had a few years ago in certain areas. But they've definitely continued some of the behaviors that got them into trouble in the first place-- with file formats, with chat protocols, etc. It happens that the Bushies don't take antitrust enforcement very seriously, so it's been largely ignored in this country. But that doesn't mean that the potential isn't there, especially if the abuses get too egregious, for them to get whacked a whole lot harder than they were the last time.

(IAAL)

It could still be right, if they have 1000 -reseller/partnership/b2b- customers.

Not that I RTFA, of course.

No, I'm just out of the office this week.