Google releases a free software called SketchUp.

Google releases a software called SketchUp. It is available in both free and commercial versions. "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".