Build a mobile or home weather station and graph the data in real time on your computer. The graph maps out wind speed, pressure, temperature, and wind direction for 10 minutes then saves the image as a jpeg and starts over.
Step 1: Anemometer build
The anemometer I built was built with materials I had on hand. I based the build around a DC motor I had that spins freely with little effort. the diagram list the parts I used.