How do you make the wind blow indoors?

So if you want to have a demo that uses an anemometer to measure wind speeds - how do you make it work indoors where there is no wind? This is a problem that John Leier (Technical Product Manager for the .NET Micro Framework) and Jim Mateer (Program Manager for the .NET MF) took on as a challenge. Inspired by all the creative fun here at Maker Faire they came up with the idea of using a DC motor to spin the "cups" of the anemometer. With changes in the speed of the motor you can simulate various wind speeds.