If you want to replace your Gnome panel with a dock, Avant Window Navigator (Docky also has a panel mode but only a few applets so it cannot fully replace a Gnome Panel) is no longer the only option as Cairo Dock 2.2.0 beta added a panel mode as well:
You can also view this video in HTML5 + WebM @ Youtube.
Cairo Dock 2.2.0 beta is available in the weekly Cairo Dock PPA.
