I'm a huge fan of wind power as an alternative energy source. Its not a perfect source and its not the holy grail that will save us from oil dependency, but it has definite possibilities. There's a couple of large windmills in my area. One provides power for a Walmart store, and the other is very close to my home and is a "functional scupture" at a park. I provides power to pump water through the pond system and irrigates trees/landscaping.
I'm in the process of planning small scale wind powered generator that will eventuall provide energy to my outdoor lighting in my yard. Won't save me a ton of money, but I enjoy tinkering with stuff like that so I'll get enjoyment out of it.
I just hope my home made windmill fares better than the one in the video below... I didn't shoot the video, I just found it on youtube. I'm just glad I was no where near when the mill met its end.