The US Air Force Research Lab is toying with the idea of letting spy drones recharge by hanging on power lines, disguised as garbage.
From New Scientist:
In addition, so as not to arouse suspicion, AFRL says the spy plane will need to collapse its wings and hang limply on the cable like a piece of wind-blown detritus. Much of the "morphing" technology to perform this has already been developed by DARPA, the Pentagon's research division. Technologies developed in that program include carbon composite "sliding skins", which allow fuselages to change shape, and telescopic wings that allow lift to be boosted in seconds by boosting a wing's surface area.