Aqua-Soft Forumscheck out the skin a dock skin on this page:
http://swizcore.com/SS/macOSX.php
Skin a dock lets OSX users put a tile\icon behind the icons as well as change the background. I know objectdock is going to have foregrounds but it would be nice to have one of the free docks be able to put a tile that gets automatically put behind each of the icons without having to edit the icon to have the background manually.
The way it would work is the background would get stretched and then the background icon would get placed behind each of the icons in the dock. Leading to it being able to look like the dock skin mentioned above or other things.