The Air Force Research Lab has created a tiny Electric Motor-Powered Micro Air Vehicle (MAV) that can attach itself to a power line to recharge itself.  It can also change its shape temporarily to look like garbage hanging from the power line.  This new ability will allow the MAV to extend its surveillance missions.

Though a prototype has not been made, the AFRL intends on conducting test flights some time in 2008.

While the idea is cool, and will, of course, present privacy concerns, it doesn’t exist just yet and might not work even if they do eventually build the thing.