Free from Google

SketchUp is a very simple-to-use 3D tool -- honestly, it is the easiest 3D software I have ever come across. And it is FREE; the professional version costs $495.

From within Google SketchUp you can retrieve 3D models and/or post your models to Google Earth (the 3D program that allows you to travel the globe, looking at addresses throughout the world).

Download SketchUp here
http://sketchup.google.com/product_suf.html
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