While I am generally against the idea of robots that aren't plugged into the wall (so you can yank that cord out when they try to kill you), I'm digging Matthias Schmiedbauer's Cargonaut concept. Something like a robotic version of Harry Potter's owl, the Cargonaut is intended to be the ultimate in point-to-point cargo delivery:

2026 - New York, Berlin, Shanghai. Millions of people are traveling through these cities day by day.

Due to technological progress in miniaturization, portable devices have become comfortable to carry. However city travelers are still heavily loaded with shopping bags, groceries or luggages which technology is not able to compress.

From now on, a revolution in personal urban transit has occurred: Cargonaut, a humanoid flight robot, comes to your current position to relieve you of your loads. After placing your bags or luggage in one of the publicly available sky boxes, Cargonaut delivers within minutes to a chosen destination.

Check out the rest of Schmiedbauer's portfolio here. (And thanks to dvice for the love!)