Google SketchUp

Classes from art to math can find a use for SketchUp. Free and powerful!

Suddenly we can all be architects.

One cool use of this I saw was when a friend of mine used it to get the exact dimensions of an object. He took and uploaded a picture of the item. Since he knew his own height he was able to use that as a base of measure and figure out the height and width of everything else in the photo.