Designing in three dimensions

If you've ever thought about designing in 3D but didn't want to invest in the software Google (rather, now Trimble) will let you do it for free! Sketchup is a terrific program that will let you model and design in three dimensions. It is fairly intuitive and there are numerous tutorials available to help you learn. It's easier than you might think.

SketchUp Intro: http://www.sketchup.com/
Tutorials: http://www.sketchup.com/intl/en/training/videos.html

Once you've created something neat you might try using these tutorials to make your designs look more realistic.

Rendering Tutorials: http://www.alexhogrefe.com/tutorials/