One of things we were most surprised to learn at West Coast Green is that there's a company in the Bay Area that's installing small residential wind turbines—and that the turbines are available nationwide. They install turbines made by a company called Skystream...
...which has a network of dealers across the US that will put up a wind turbine for you. A small model—which will fit not only in a convention center, but in small urban backyards—at peak output, it produces 1900 watts (that's enough for a very, very energy efficient house.) It's connected to the electric grid, so any excess energy you produce flows back into the grid for use elsewhere; in some places, your electric meter will actually run backward.
We were quoted an installation cost of about $17,000 in California's pricey Bay Area. That's steep, yes, but it's still a relatively small percentage of the budget if you're building a new house, and one which will seem like a great deal every month that you get an electric bill for $0.
More information at www.skystreamenergy.com.
image via Skystream