I think he's talking about a virtual desktop application.
Apple calls there's "Spaces" and it's built into the OS. You have one monitor, but 3 virtual monitiors and you can move applications from one virtual monitor to another. You can configure several virtual screens/virtual desktops
[IMGNOTHUMB]http://files.me.com/tlhintoq/apeo0b[/IMGNOTHUMB]
Then drag applications from one screen to the other. Here we see Vuse on screen 1, iTunes on 2, nothing on 3, Excel on 4 with some artwork showing it could be dragged to the left to put it on 3.
[IMG]http://files.me.com/tlhintoq/fvy6pt[/IMG]
Pressing a key combination such as [CONTROL]-1 takes you to screen 1, [CONTROL]-2 is screen 2 and so on. In Apple's implimentation you can also just drag a window to the right/left/top/bottom of the screen and you will be switched to that virtual monitor: You don't *have* to go to the reduced view to move windows. It does a decent job of giving you multiple desktops.
There's several different ones out for Windows such as:
http://virtuawin.sourceforge.net/
or
http://news.cnet.com/8301-13880_3-9902461-68.html