Though one extra display is great, two is even better. If you're lucky enough to have the new Macbook Air, then you can rig up two Thunderbolt displays. If not, you can still enjoy a power user multi-monitor setup by using your iPad as an additional display. AirDisplay, an impressive retina display capable app for the iPad, offers a wireless solution for connecting your iPad (now also available on Android) as an additional monitor for your Mac over wi-fi.
In my case I've setup a retina display iPad running AirDisplay and a 24" display to compliment my 13" Macbook Air. In my day job as a designer and developer, multi-tasking is a must, and being able to run the Adobe Suite across multiple monitors on a slick machine like my Macbook Air really is the ideal.
(Images: Sean Rioux)