clipped from www.engadget.com

We've seen some interesting solutions to keeping UAVs powered for extended missions, but none so diabolical as actually landing on the enemy's power lines and using their juice to power up. That's the plan behind the Power Line Urban Sentry (PLUS) project currently being run by the Air Force Research Laboratory and private firm Defense Research Associates, and it's already yielded UAVs that can land on power lines and charge in three hours. The project started with attempts to charge by simply flying near power lines, but when that method yielded only micro-watts of juice, focus shifted to actually landing on the lines.

the team is also working with an outfit called the Center for Morphing Control to disguise the UAVs when they sit on the lines -- so far, they say, they've made a small UAV "look like a Coke can."