Many "virtual" monitors on your desk – Macitynet.it
Imagine being able to have 100 monitors simultaneously connected to your computer. Imagine that different windows and applications can be displayed in each of these monitors. Finally, imagine that you can have the screen present in each of these monitors immediately.
Virtual Desktop for Mac OS X is a $ 20 shareware application that does just that: it offers the ability to have multiple virtual monitors instantly recallable at any time. The handy application for those with a window that is always too crowded.