The Skystream system is unique for being the first all-inclusive wind generator with controls and inverter built-in. Produces approximately 400 kWh per month in a 12 mph average wind speed.
They've come down to about $7 to10K fully installed. http://tinyurl.com/2japqm
For a home that is fully electric (appliances and heat) that's getting pretty affordable... payoff estimated to be about 5 years and providing that the power company allows Interconnection with the Utility, excess power can actually be sold back to the utility via net metering.
I like it all... we have an average wind speed of about 14-15mph in our valley :-)