Easy homemade anemometer, this goes together quickly if you have the parts laying around. This is basically a mini wind generator; the spinning motor produces a current that a multimeter reads.
Inspiration for this project comes from http://www.otherpower.com/
1 cheap $3 analog multimeter
3 or 4 easter eggs*
1 telephone wire with ends clipped off
3 or 4 - 3" screws*
1 DC motor out of CD ROM drive
1 circular wood cutout from hole saw
1 hose clamp or bracket for motor mounting
1 broomstick or pole
Extras: whiteout, solder, super glue, and electrical tape
*"3 or 4" refers to how many cups you prefer on the rotor.