It seems like in the 21st century the imagination should be opened up for all sorts of flying machines. Minaturization of computing technology should allow some amazing computer controlled stabilization. That should enable fly by wire objects that aren't naturally stable or are very hard to control. Obviously, more conventional craft like helicopters, should become controllable by people with little training. With light weight control materials like the new artificial muscles being developed, seems like there is an opportunity to "morph" craft like we've seen in so many cartoons over the years. It really may be about the time where technology is going to enable a vast array of potential solutions to low cost personal flying.

Materials advances allow ultralight weight craft, but of course at a minimum if you are carrying people, you have their weight. At relatively low speeds you probably won't need much beyond some simple construction to hold the engines and people (jetpack!), since your aerodynamics isn't that big of deal.

Then you get to the powerplant and engines. What engines will give you the thrust ratio, to lift people and fuel and enough power for the computer controlled stabilizization to have a safety margin? Where is flywheel technology these days? I remember reading articles years ago, about the potential to store incredible energy in flywheels. With new materials, maybe people are getting closer to more compact and high energy flywheels that could drive the engines for this mythical personal flying craft.