I can see the need for two monitors. I work with two monitors, it is handy to have your email application on one screen and your messages on another. It is great to click on a new window in an internet browser and have both windows up simultaneously. Matrox thinks I might need four monitors, because their new M-Series feature a quad head GPU.

Maybe I can see how you would use this if you are a software developer and need to see multiple threads of code at the same time, or maybe if you are monitoring security from a few inputs AND trying to play solitaire. None the less, the Matrox M-Series PCIe X16 video cards have 512 MB of memory and will support up to four VGA or DVI monitors. You can have them set-up as one screen or independent displays.

The cards are set to go retail in September and will start at $259.

Source.