An annoying little toy originating in Germany
, this device started out as a training device
for peoples' wrists
A Gyrotwister consists of a wheel that can spin at several thousand rounds per minute, that is rigged up inside a semi-transparent ball so that it can also move around a horizontal axis, in much the same way that the earth spins around one axis one time a day, but spins around the other much slower.
If the user can make the Gyrotwister go fast enough, it can produce resistance enough to make it feel heavy, which in turn makes the user apply more energy, again making it go faster. Some variants, particularly one called XBeam, have a dynamo inside that produce patterns of light as the wheel spins around, and one can usually measure the speed at which the wheel is spinning by putting a microphone up to the device.
It's highly addictive, though it's not recommended in combination with excessive typing (e.g. noding) and certain auto-sexual practices.
Xbeam is currently known to be sold in Germany and Norway.