If you would like to design your dream home, car, or anything that you can think of…without the complexity of AutoCAD, then you have got to try SketchUp. I’ve used it to design some furniture I have eventually built. It is very easy to use and can be incorporated with Google Earth. Now that Google has purchased SketchUp you can download it for free here!
"Google SketchUp (free) is an easy-to-learn 3D modeling program that enables you to explore the world in 3D. With just a few simple tools, you can create 3D models of houses, sheds, decks, home additions, woodworking projects – even space ships. And once you’ve built your models, you can place them in Google Earth, post them to the 3D Warehouse, or print hard copies." Description Via Google’s Site