Glass2k - Small little program that allows Windows 2000/XP users to make any window transparent.
SmartSystemMenu - SmartSystemMenu extends system menu of all windows in the system
RBTray - Allows almost any program to be minimized to the system tray by right clicking its minimize button.
Stay On Top - Set a window to stay on top with this single-function but handy application.
Clicky Gone - Clicky Gone allows you to hide your selected windows from view, this includes the taskbar button...
DeskPins - DeskPins can be used to make any application topmost, that is, to keep it above all other windows.