I've mentioned how great Atom in a Box is for orbital visualization many times, but it's only for the Mac. If you want a good visualization program for the PC, you might want to try Quantum Atomica:

Quantum Atomica presents a very pleasing and easy-to-use interface that takes you step by step through the configuration process.

Then you simply click "calculate" to view the orbital visualization:

You have complete 3-D control over the model and can manipulate it along any axis. The main view window can be used for 2-D or 3-D perspective. Several other options are available too.

But lets face it, to many of us, quantum mechanics is about as understandable as the arguments on the Jerry Springer show. That's where Quantum Atomica really shines - it has a built-in help section that provides a well-organized quantum mechanics tutorial.

It's hard to believe, but Quantum Atomica is free! There are no shortcomings to this program that I can see, and it is exceptionally easy to use. Download it today and give it a try!