From Martin Jetpack's website:
Since the beginning of time man has dreamed of flying as free as a bird. Today, that dream is a reality. The Martin Jetpack is the world’s first practical jetpack.
The jetpack has been a major goal of the aerospace industry for over fifty years - a goal that has been achieved by Martin Aircraft Company. The Martin Jetpack is a result of years of input from a team of engineers and developers worldwide.
Originally designed with the leisure market in mind, Martin Aircraft Company has seen strong demand from a wide range of markets, including military, civil defense and recreation. It is in the final stages of research and development to meet early interest from the defense and civil defence sectors.
From The Atlantic:
Just about anybody could use what will be the first commercial jetpack, according to Martin. (That is, if you're able to get your hands on one: More than 2,500 people are on a waiting list.) "You just strap it on and rev the nuts out of it and it lifts you up off the ground," Martin told a reporter for the Daily Mail after completing a seven-minute outdoor flight with his team by remote control.
"It's just basic physics. As Newton said, for every action there is an equal and opposite reaction. So when you shoot lots of air down very fast you go up and you're flying."
Even though it doesn't require much skill, it's unclear how the aviation industry will respond to the pack. Because it only weighs 250 pounds, customers in most countries won't require a license; the U.S. Federal Aviation Administration has yet to make a decision as to the product's legality. Either way, Martin's company will require all owners to participate in a training program before they can fly.