Here is a list of companies that sell small wind turbines and systems for residential use.
Bergey Windpower Bergey Windpower is one of the world’s leading suppliers of small wind turbines. They have 30 years experience, installations in all 50 U.S. States and more than 100 countries, and an international network of 500 dealers.
Gaia-Wind Ltd. Gaia-Wind develops and manufactures small, proven and efficient small wind turbines (commercial & domestic).
Southwest Windpower Sells a variety of small wind turbines for residential, farms, and businesses. This page on their site shows some of the types they offer, and has a comparison sheet you can download in PDF format.
XZERES Wind Sells the XZERES 110 AND 442SR models along with windmill towers and other wind power products.