Think about it. You can create furniture models easily and then design the new interior decor of your house. You can animate and share the videos. And many models are available for your use to play with for free. The program can access the net to get whatever it needs.
There is a free version and also a more powerful Pro version:
With the Google 3D Warehouse, everything you might need is already out there for you to quickly mock up your city, town, school project or that new bedroom set.
With the new version objects that are smarter and know how to react to you. drawing hints that are clearer and more consistent.
Google Sketchup [Google.com]