There are several wind powered microturbines available on the market these days. Some claim that they can operate with wind speeds of only 2 m/s - the problem is, who knows what a wind of 2 m/s feels like? This map is a graphical representation of US regions that are conducive to operating microturbines. If you have more information - add it!
There's another great resource here, but it's just too much data for this wiki - it shows the average wind speed monthly in hundreds of US cities: