Power management hot keys in OS X: If you need to shut down or restart your Mac, you can do so using quick hot-key sequences. [Read more]
Sleep the display
A final power mode option that Apple supports is display sleep, which can be handy for quickly killing the output to your monitor without shutting down the system, sleeping your computer, or turning off your monitor if you have an external display. This will maintain full function of your system, so you can continue any ongoing tasks you have running. To do this, press Shift-Control-Eject on your keyboard.