Researchers at the Stevens Institute of Technology have designed and built the prototype of a WiFi hacking air drone based on the AR.Drone quadcopter. They added a lightweight single board computer with Debian Linux installed, along with 3G mobile broadband connectivity and two WiFi cards (the second for packet injection.) A GPS receiver and sonar module are also onboard providing latitude, longitude and altitude readings.
Once airborne the SkyNET can locate, attack and infect other computers via WiFi. Its remote control capabilities allow the operator to control the interaction with these hosts making it possible to establish botnets.
You can download the 15 page PDF explaining this research project here.