Use the force of compressed air to move a "vehicle"
http://www.energyquest.ca.gov/projects/air-power.html
Make a device to measure wind speed.
http://www.energyquest.ca.gov/projects/anemometer.html
A simple gauge to measure how strong the wind is blowing.
http://www.energyquest.ca.gov/projects/windmeasure.html
Make it yourself cartoon kit
http://www.exploratorium.edu/science_explorer/flipstick.html