|The beautiful looking Cairo Dock...|
Anyway, if you use both Mac OSX and Gnome desktops but while on Gnome, you must be missing that "docky!" :) for sure then. If that's the case and if you're searching for an alternative to that... then Cairo Dock is the answer. Even the official developer claims that he's trying to make a replica of that "Apple dock" as well.
They recently released a new version which integrate better with the upcoming Unity desktop too.
*. Fully supports the OpenGL API (you know for delivering those 3D looking fancy graphics).
*. Built in applets such as - keyboard indicator, mail, quick browser, Toons, weblets.
*. Disk space showing applets.
*. Recently added the KWin support (KDE window manager).
*. Various hoover effects.
*. Assign keyboard shortcuts.
*. You must have Compiz installed (if you use a recent version of Ubuntu such as 10.04, 10.10... then it should be installed by default).
*. Change themes... are just a few to name.
So if you run Ubuntu and want to give Cairo dock a try, then open your Terminal and issue the below command to install it - the 2.3.0 version (using a PPA channel).
sudo add-apt-repository ppa:cairo-dock-team/ppa
sudo apt-get update
sudo apt-get install cairo-dock