Here is another brilliant piece by kinetic artist Arthur Ganson. This machine was built for the World Sculpture Racing Society in Boston.
According to Arthur Ganson:
The cast hand is my own and the pen, controlled by three cams (x, y and z axis), moves in three dimensions and writes the word "faster!" on an index card while being pushed down the street. The faster the cart is pushed, the faster it writes. Warning, an out of control feedback loop between creator and creation can result in dangerously fast speeds and certain death.
See more kinetic art by Arthur Ganson on his web site.