how to rotate the orientation of my monitor in OSX 10.8?

My girlfriend just bought a great monitor (EIZO CG223W) for her macbook, which you can rotate 90º in portrait mode.
The screens didn't flip along, and I couldn't find a setting in the system preferences.
I remember (in pre 10.8) there used to be a setting in the screen panel, but it's vanished.## Heading ##

After some research i found this blog, which perfectly detailed explains how to get this hidden setting:

1. Open the system preferences
2. Hold down the command and option keys while clicking the display icon
3. Next locate the screen adjustments on the external monitor and you will notice now there is an option called "Rotation".
4. Choose 90 Degrees and now your monitor is in portrait mode.

Thanks roadzy and OSXdaily!