Try holding option/alt on most controls, it usually have something nice hidden. E.g. alt+clicking the button that shows/hides the notification center (that's t

Try holding option/alt on most controls, it usually have something nice hidden. E.g. alt+clicking the button that shows/hides the notification center (that's the name?) will toggle notification popups. Another one, alt+clicking the wifi will display additional data about it. Holding alt while right clicking on an app in the dock will toggle between "quit" and "force quit" as well. Etc.