Actual Title Buttons lets you add the new Minimize To Tray, Stay On Top and Make Transparent buttons to any program's title bar next to the Windows standard Minimize/Maximize/Close buttons.

The new buttons are as easy to use as the standard ones: you can minimize any window to system tray, force it to stay on top of other windows or make it semi-transparent with a single mouse click.
More info:
hxxp://www.actualtools.com/titlebuttons/index.shtml