Dockyard

Dockyard is a "dock switcher" for Mac OS X. It allows you to have multiple docks and switch between them with one click.

You can even switch Dashboard configurations along with your dock. Instead of a normal application, Dockyard is a menu extra, meaning it appears in your menu bar. You must get a program like Unsanity's Menu Extra Enabler to allow it to work, as a restriction on third-party menu extras has been imposed as of Mac OS 10.2. After you install one of these programs, just double-click on Dockyard.menu to launch it. From then on, it will always be in the right side of the menu bar. To remove Dockyard from the menu bar, command-drag it out. Although most of Dockyard's bugs are gone, it is still recommended that you back up your Dock before using it. If your Dock won't switch, try logging out and logging back in.
What's new in this version:
Universal binary