I'm looking forward to emulate the behavior of OS X Dock Stacks so that I can have, for instance, one stack for browsers and another one for IDES. People at ask ubuntu are doing a lot of cleaver stuff with custom Launchers and Quicklists (see List of custom Launchers & Quicklists for Unity). So has anyone figured out how to have stacks in Unity? Anything fancier than a static Quicklist over a dummy folder icon?
Give a try to Cairo Dock, whose interface is easy to set up as you wish and its gadgets includes stacking with several fancy features.
Screenshot from my Desktop:
More screenshots from the net:
Parabolic style sub-dock:
Dock over dock style
Slide style sub-dock
Rainbow style sub-dock
Sorry, I forgot to mention the Panel Mode, which is cool, an illustration is placed here:
Check out Drawers.
You can put just about anything in a drawer by drag and drop. You can even nest drawers inside one another. See below for a screenshot. It's been submitted to the software center but is awaiting review.
In the meantime, to install drawers run the following in a terminal:
Then create your first drawer by opening the dash and typing Drawers.