Cairo-dock is an animated application launch bar for the desktop comparable to Mac OS X's Dock, or Rocket Dock (for those of you who come from Windows).
It is compatible with Compiz-Fusion, Beryl, Compiz, and also Xcompmgr, but it can run without a composite manager (with fake transparency). Cairo-Dock can run under GNOME, KDE, and XFCE.
gDesklets is a system for bringing mini programs (desklets), such as weather forecasts, news tickers, system information displays, or music player controls, onto your desktop, where they are sitting there in a symbiotic relationship of eye candy and usefulness. The possibilities are really endless and they are always there to serve you whenever you need them, just one key-press away. The system is not restricted to one desktop environment, but currently works on most of the modern Unix desktops (including GNOME, KDE, Xfce).