I recently read about Docker, a cool program for the Mac that modifies the Dock using hidden system settings. It is pretty cool. With it, you can customize the Dock in many ways. I am running Leopard, and was trying to find a way to revert to the exact 2-D Dock that I had in Tiger. Unfortunately, you can’t make the entire Dock look like Tiger’s 2-D Dock. A 2-D option is available, but it doesn’t look the same. But it if you prefer the black arrows in Tiger’s Dock that showed which programs were running, you can bring them back. I do like the fact that I can color the 3-D Leopard Dock any way I want. I set the background to solid black and it looks very nice with the icon reflections.
Docker does much more than just change the appearance of the Dock. Options are also included to modify behaviors and add new Stacks. Docker is free, but donations are welcome.