Yesterday Boeing announced that one of its pilots recently took to the air in an airplane powered by hydrogen fuel cells. This marks the first time a manned aircraft running on fuel cells has ever successfully completed a flight, though robotic drones have done so in the past.

Two years ago we wrote about Norwegian engineer Petter Muren's effort to build a mini copter weighing only 3.3 grams. that radio-controlled craft, the Picoflyer, could take off from the palm of your hand. Now Muren has designed the larger but more capable Black Hornet.

Behave yourself in Miami, because the eyes-in-the-sky may soon be watching. We're still not sure about all those rumors concerning insect-sized flying vehicles keeping watch over cities, but larger versions certainly seem to be on the way.