While Docky is still a favourite among Ubuntu users, panel replacement app ADeskBar replaces both the Menu Bar and Taskbar in Ubuntu, adding a few other features to the mix as well like quick Terminal access, stacks and a quick search box.
If you're looking to consolidate some of the space on your Ubuntu desktop (and Unity just doesn't do it for you), ADeskBar is actually a pretty neat panel replacement. Not only do you have the typical taskbar on the bottom of your screen, but you can also access the Ubuntu menu, wireless and sound preferences, and everything else from the menu bar (except for the indicator-applets).
You also get some other cool additions like stacking applications into one taskbar entry, a built-in popup Terminal, a popup Google search box, and a few cool themes with which to tweak it. It's a nice lightweight replacement if you're looking for something different, and does a good job of consolidating all your on-screen controls into one dock. Hit the link to check it out.