Some applets deposit icons in the system tray of the KDE or Gnome task bar. If you don’t use KDE or Gnome but you still want the system tray applets, check out Trayer.
If you have given up hope of ever finding your way around the mess of data on your desktop, a desktop search engine can help you penetrate the gloom. Kerry and KBeaglebar bring the Beagle engine to the KDE desktop.