Cinema Display to iMac as Second Monitor
I am using my 2005 20" Cinema Display as a second monitor to my new 2011 iMac. The monitor works great! I was able to use the thunderbolt to ADC adapter to connect the monitor to the iMac.
The only technical problem that I ran into was that I could figure out how to adjust the display contrast. I discovered that connecting the USB port to the iMac allowed me control the contrast. I also gain the use of the additional USB ports in the back of the Cinema Display.
The other problem I had is the monitor is not the same height as the iMac. Once solution was to use the Quirky Space Bar which lifts the monitor and added 6 USB2 ports. The problem that I found with the Space Bar is that it lifts the monitor an extra inch and a half more than I needed.
What I found that worked perfectly is the Steve Jobs Biography hardcover book! I discovered this by accident while trying to figure out the exact height that would work. What a great use for the book after reading.