MediaDock is a simple companion to Apple's Dock, providing a place for mounted media such as CDs, DVDs, Disk Images, and Hard drives to reside. Just like the dock, MediaDock allows you to enable hiding as well as pinning with a twist - centered pinning keeps the dock centered on it's side of the screen; top pinning keeps the top left corner of MediaDock fixed, meaning mounts and unmounts cause the bottom of MediaDock to move. Why? Because you may want MediaDock to be 3/4 up the left hand side of the screen instead of all the way up to the menubar - dragging the border makes the choice in positioning yours. MediaDock gives you easy access to applications scuh as iTunes and iDVD, as well as directory access to files and folders on mounted media.
The source code is available.