Let's imagine you're out having a nice walk in the middle of the countryside when you start feeling peckish. Using Cambridge Consultants' DelivAir app, you'd place an order for a snack, and the delivering drone would use GPS and your smartphone signal to navigate to your location, periodically asking for location updates during its flight, until it's within visual range. Once it arrives, you point your mobile phone flash LED to the sky, where it'll blink a coded pattern to let the drone know it's delivering to the right person. Then, while staying a safe height above the ground, the drone lowers the package into your very hands using a stabilising winch, which you then unhook. The drone then makes its merry way back to base, and you've got your snack, or whatever else it is you urgently need in the middle of countryside.

Of course, there are multiple applications for this type of service, fervent consumerism aside. It could be used to take a puncture repair kit to a stranded cyclist, or essential supplies to remote areas as part of disaster relief efforts. There's life-saving potential, too; DelivAir could swiftly get EpiPens or defibrillators to people in urgent need. "Drone delivery is fast and ideal for something that is needed immediately. In that case, a consumer wants a delivery directly to them as a person – not to a location," said Nathan Wrench, head of the industrial and energy business at Cambridge Consultants. "Our DelivAir concept has the potential to revolutionize the delivery process, by removing the address restriction that other drone technologies are limited by."

Indeed, DelivAir's ultra-precise delivery concept makes perfect sense for drone application, but as is the case with Amazon, 7-Eleven and other drone delivery champions, there are still question marks hanging over the mainstream roll out of this kind of service. Instant gratification is a shopper's dream, but a once-blue sky dominated by hundreds of buzzing delivery machines sounds decidedly dystopian. Still, unlike Amazon's plans to rain packages out of the sky, at least DelivAir's concept -- which places the package neatly in your hands -- retains some social decorum.