Boeing and JetBlue have backed a little-known company called Zunum Aero -- and for good reason. The startup is three years into the development of small planes powered by hybrid-electric propulsion, which it says can "pave the way to a golden era of fast and affordable electric air travel." Zunum's planes promise to make local flights a more feasible alternative to traveling by car or high-speed trains. The 10-to-50-seater aircraft will cut travel time by 40 to 80 percent, so if you're flying a flight that typically takes five hours, it'll only take two-and-a-half hours. Thanks to the planes' lower operating costs, seats will cost 40 to 80 percent below current prices, as well.