Cairo-Dock, Docky and AWN are popular launchbars for linux, if you just installed Ubuntu 10.10 Maverick Meerkat you may want to try one them.

Cairo-Dock is an animated application launch bar for the desktop, comparable to the dock in Mac OS X or Rocket Dock (for Windows). It is compatible with Compiz, but it can also run without a composite manager. Cairo-Dock can run under GNOME, KDE and XFCE.