Google Sketchup

I have heard about it, but never checked it out. It's a free 3D CAD-like tool by Google.

Here's some great vids:

http://sketchup.google.com/training/videos/new_to_gsu.html

I put this together in about 1:15, my new shed layout to show wifey since she's out of town. That included the time to watch the videos!

I didn't do the roof, so assume that it goes up from the shown lofts ;)