I just saw an amazing little video on the Crazyflie Nano Quadcopter. This thing is so cool! I am going to try to talk the wife into getting one. One of the neatest things is that they are open source and moddable so you can change it's mechanics and software to what you want.
I'm curious if you could control it with a Raspberry Pi to increase mobility. Or even have two of them carry a Raspberry Pi with a pre-programmed route and do some long range reconnaissance missions.
Oh and here's a video.