The creators of "Micro Helicopters" are pushing the technology envelope by integrating lightweight, powerful batteries and motors, carbon fiber materials, and miniature electronics into tiny controlled flying machines.

Weighing in at 6.9 grams after almost 6 years of effort and refinement, Alexander Van de Rostyne has pushed the size and weight of the Pixelito down about as low as possible. The little chopper is controlled by an infrared signal and uses a very lightweight, 1mm carbon continuous frame that comprises the skids and the canopy protection around a very simple motor and flight mechanics design.

Check out this video of the little fellow flying around a living room.

There's a really nice library of links, Collective Ptich, on R/C helicopter technology. These machines are an incredible combination of mechanical engineering, electronics, materials, and ingenuity. I think it's fascinating to see what people are doing with them. Here's a video of a guy who took his micro-helicopter, a "Piccalo", into an inverted hover and then landed the skids on the ceiling of the room he was flying in. A good website selling micro (and traditional sized R/C) helicopters is helihobby.com

Helicopters have been a great way to introduce various physics lessons to my 8 year old son (plus his old-man gets a big kick out of them, too.) He's starting to learn Newton's 3rd law through asking why a helicopter has to have a tail rotor.