That game looks line an Internet version of "Rush Hour" by binary arts. I know there's a palm pilot version available too, but nothing beats the original in my opinion. If you get a copy you will truly learn what addiction is about.
I've spent many hours playing rush hour - the game comes with 40 puzzles, and there are 120 additional puzzles that you can buy through expansion packs. Some of the top ones are really tricky.
Here's a link to the website if you're interested. It's very satisfying to physically slide the cars around to get the red car out.