Control iMac and LED Cinema Display Brightness Simultaneously

I have a iMac 27'' and a LED Cinema Display 27'' connected to it. And I've noticed that to be able to control brightness I need to open the Display.prefPanel and modify the brightness of the displays individualy.

Is there a way to do this simultaneously? Maybe with a third party app? If not, is there a way to assign a keyboard shortcut to the second display brightness?

Solution 1:

I just started using Dimmer Than Dim, a free app in the App Store. I only have one display (iMac), however.

Solution 2:

F.lux is worth a look, it changes the colour temperature and brightness of your monitor(s) based on the time of day.