Here's another form of alternative energy that's frequently overlooked: a wind turbine for the home.
It works like any other wind turbine, but the SWIFT turbine is a lot smaller and quieter, thus avoiding the potential problem of collapse and calamity. There's even a helpful calculator -- put in your address, and get a map back that shows you the potential for wind generation at your home, complete with links to relevant incentives.
They'll go on sale in the US in July 2008 and have a projected price of $10,000 to $12,000, with many local and federal incentives available to offset that cost. According to the FAQ, one properly placed SWIFT turbine can make 2000 kWh of electricity. Combine that with some PV panels, good building insulation, and efficient appliances and you could get close to zero net energy.