Solder some leads to the motor terminals and connect to a voltmeter. If you use a hairdryer or blower to turn the propeller quickly, voltages of up to one volt can be produced.
Using a bit of papier-mache and some paint, a whole wind farm can be created which gives pupils a greater understanding of how renewable energy can be created.
Experiment with different shaped blades to get a more efficient propeller (and therefore a higher voltage). You could even replace the voltmeter with a low voltage LED to give a more visual representation of the voltage being produced.
Technically speaking a ?wind turbine? is a device for turning the kinetic energy in wind into mechanical energy. If this mechanical energy is used to make electricity it is then called a ?wind generator?.