Jet Pack: You strap a jet engine to your back and go screaming into the sky. Perk: no one hears your cowardly cries over the screech of the jet. You get maybe thirty minutes of fuel, so don’t waste time looking for a better parking spot. Companies that are developing and demonstrating them, such as Martin Jetpack, are focusing on the emergency response market to start with.
Tech Level: High. These are just emerging now and I expect they’d be nearly impossible to fly without sophisticated computerized controls. Best genre fit: Near Future Military SF.
Appeared In: The Rocketeer. I know what you’re thinking: that wasn’t a jet pack, it was a rocket pack. However, it was fueled by alcohol only, and carried no oxygen supply. So, despite the name, it was a jet pack, and according to TV Tropes it even had a compressor stage. Conversely, when I ransacked the internet looking for fictional jet packs, nearly everyone was actually using rockets. Go figure.
For Your Plot: The Martin Jetpack has a gas tank the size of a small car’s and burns through it in about half an hour, so giant plot holes destroy the space-time continuum if your hero gets two hours of flight time out of a fuel tank smaller than a motorcycle’s.