Just think, the possible demise of the pizza delivery driver. This gadget promises to deliver your fast food by air to your GPS-defined location.
At a distance, it looks promising. As you get closer, some details probably need to be worked out. The developer, in San Francisco is suggesting it deliver tacos, possibly because of a limited payload capability. I suggest making it a hybrid, with a gas motor/generator powering the electric motors. Routing the exhaust around the cargo compartment would keep the munchies warm as well.
As to making the delivery, I don't know about you, but looking out my front door, I see tall trees, overhead power lines, and nowhere convenient to set down long enough to offload a bag of tacos or a medium pepperoni except in the street. The back yard doesn't serve any better either.
Still, given a human operator to help out, getting the thing to the right address should be automatic, and with help from the human, getting it to the ground becomes more manageable. Add some learning capability, and the next run could well be autonomous.
Just remember to stay clear of the rotors until they have stopped turning before unloading your food.
Super-size that soft drink for you sir?