This guy builds a nice wind rotor for home power generation. He claims to get 1000 Watts Average in 20MPH Wind. Either way, the design is attractive, scalable, and doesn’t look like it will scare the neighbors too much. Check it out!
NOTE: since this was posted, the listed page has been removed. Here are two more links to low-cost vertically constructed turbines:
and a smaller scale project to whet your appetite: