DockFun! is a simple, smart utility which lets you have an infinite number configurations of your dock, so you can organize all your applications in tidy & cool sets – version 4.0 Beta2 is now available. Then you’ll choose which dock you want turned on with a single click. For example, you can have a dock of internet applications on the left part of the screen to create more room for the browser window or you can have a dock with huge icons and great zoom effect for show how Mac OS X rocks. DockFun! is also a great tool for enabling all the hidden preferences of the dock, such as placing the dock at the top of the screen.
More info, screenshots, and download link here.
Great App.. I love DockFun!