This is a really cool app.. Down load the free part and have fun. Don’t forget to look at the helpful videos.
Google SketchUp 7
Create 3D models and share them with the world
Google SketchUp is software that you can use to create 3D models of anything you like. Build models and add them to Google Earth »
Get started right away.
Most people get rolling with SketchUp in just a few minutes. Dozens of video tutorials, an extensive Help Center and a worldwide user community mean that anyone who wants to make 3D models with SketchUp, can. Check out our training videos »
Model anything you can imagine.
Redecorate your living room. Design a new piece of furniture. Model your city for Google Earth. Create a skatepark for your hometown, then export an animation and share it on YouTube. There’s no limit to what you can create with SketchUp.
Pasted from <http://sketchup.google.com/product/gsu.html>