Wattbot

Free web-based service that shows people how to determine how much energy they use. Consumers input information about their home and lifestyles to get recommendations for the best products and services that will save energy and money. Providers of the products and services buy the leads generated by consumers seeing the recommendations on the site.

This was the winner of the Green:Net Launch Pad contest. If they can make it simple to use and get providers to sign up, this will be a very useful service. Here is a video of how it works: