SEM (scanning electron microscope) image of a dust mite approaching a gear train. The gear train is microscopic in dimension, each gear tooth is smaller than a human red blood cell. The gear train is connected to a microscopic motor and acts much like the transmission in your car, but it is so small that you can not see it without the aid of advanced scientific microscopes. This device is an example of real things being made with nanotechnology.
Image Source: Sandia Labs [H/T: Norm]