I am doing my best to cut my bottom line costs to 'run' my house. The fact that Mother Nature benefits is a bonus (sure, I'm selfish

)
I've replaced my 300 watt lights with CFLs, looking into wood as a heat source (instead of my current oil), sealed all my windows with removable caulk for the winter, and improving insulation everywhere. I also bought one of the energy meters that you plug into the wall, and then plug your appliance, lights, whatever into to see its load. It measures amp/watts/volts and does all the related math for you. You can even add your kw/hr cost to get a dollar value for the appliance in use. I bought it more for interest sake. I sleep better knowing my daily coffee costs 0.7 cents, and my superb rotisserie chicken that takes 1 1/2 hr to make only costs 7.8 cents
Glenn, by no means do I want to go into too much depth here, but there is a lot of conflicting data on the Prius, in terms of it's environmental footprint. It may be more efficient once it's built, but the energy needed and used to create the batteries, and to eventually dispose of them, outweighs some of the benefits.