Currently Being ModeratedMay 22, 2013 6:36 AM (in response to JAMinard)
I just found this nifty little program that allows me to FINALLY control the brightness of my monitor (23" Apple Cinema HD Display (M8537ZM/A) (Acryllic Frame). It's a quick download and doesn't require a reboot after install. It does require Microsoft Frameworks 4.5, and it will prompt you to visit the download site. BUT OMG, finally, finally... Here is the site:
Make sure to review which Apple displays are controllable with this program.