*. Files and folder search within your PC.
*. Online search (Google, Bing, Yahoo, e-bay, etc).
*. Heck.. it even comes with a calculator.
*. del.icio.us Bookmark search.
*. Turn-off, reboot, stand-by your PC directly through the app.
*. Launch apps or recently used documents.
*. Wikipedia suggestions.
*. Yahoo suggestions.
*. Window switcher... are just a few to name.
So if you want to install Gnome Deskbar applet in Ubuntu, then open the Terminal and issue the below command.
apt-get install deskbar-applet