This Instructable will give you a step by step process on how to carve a real wind turbine blade out of wood (not those fake ones from a 4" PVC pipe, but they are cool too.). This was designed by me, a real Aerospace Engineer, using real airfoils, and optimized for a small wind turbine at lower starting wind speeds.
I promise you it is easier then you think. I will even provide you with a pdf drawing that you can print out, and use as a template. So I want everyone to start making wind turbine blades. Well, what are you waiting for, GO!
If you are interested in how to design your own go here:http://www.aerodyndesign.com/SMALL_WIND_TURBINE/SMALL_WIND_TURBINE.htm
By the way, after you make these you need to make a hub, but that is easy too. And make or buy a motor, but you can get them cheap on Ebay. Just type in PMG (Permanent Magnet Generator). They are nice because they do not require a gear box because they operate at relatively low RPM (500 RPM for this blade).