Pic 30Scott writes “Alexander Van de Rostyne has been designing and fabricating ever-smaller micro-helicopters out of advanced materials, batteries and remote control systems for the last six years or so. The latest has 4 channel control and weighs in at 6.9 grams ( 1/4 ounce ) with battery.” Link. The site has tons of photos, details on the miniaturization efforts and hamster comparisons.