I've pulled a couple of stepper motors out of an ancient bubblejet printer.  I plan to make a lenz2 turbine, about 40cm in diameter, either directly mounting the motor, or using the toothed belt that I pulled out of the printer.

I'll be using some 2mm plywood, PVC halfpipes for the vanes, and I'm not sure how to join them to a hub and axle yet.

see http://www.windstuffnow.com/main/lenz2_turbine.htm for more info on the turbine design.