I'm interested in hooking up four LCD monitors to my computer.  Digging around for adapters, I found that Matrox makes an adapter called TripleHead2Go in two versions -- analog and digital.  
 
Is this the only product out there that will allow more than two displays?  Thank you for your help.
 

How do you want to use your four monitors?  Four separate displays?  Or a single display spread across the four monitors?

I'm not sure yet... I want to use two as a spread for sure and the other two could be setup seperate because most of the work is done on two monitors.  The third and fourth display would show graphics and results of teh work done on the two main monitors.  
 
What would be my options?  

From the THG Article AMD's New 780G Chipset  In that article they used the motherboard graphics for 2 monitor and an ATI HD 3450 video card for the other two monitors for a low cost solution to run 4 monitors.

Besides the option in the article above you have quite a few options actually.  Most video cards can run two monitors.  And most motherboards can have two video cards - usually 1 PCI-E PowerColor HD2600Pro PCI-e $48 and 1 PCI Powercolor HD2400Pro PCI $45 for example.
The slightly more expensive Crossfire or SLI motherboards can handle two standard PCI-e video cards.
Having a display spread across two monitors is usually called Span mode (also called stretched mode).

Alright... so I have a PCI-express card already installed in the machine.  If I added a second PCI-express  card in an available x1 slot, would that allow me to span or would that limit me?    
 
BTW... the link to that article didn't work.    
 
Thanks for your help WR2.

link for article:  http://www.tomshardware.com/review [...] ,1785.html
http://www.tomshardware.com/reviews/amd-780g-chipset,1785.html

You should be able to span 2 monitors with your current PCI-e video card assuming you can hook up two monitors.

There are a few PCI-e x1 video cards out there but not many.   Probably be easier to find an plain old PCI video card.
A PCI video card would go into one of the PCI slots - not a PCI-e x1 slot.  

Right now I have two monitors hooked up so it does work.  Was just curious about the other two I want to hook up.  Thanks for the clarification... PCI is what I meant.    
 
If I plugged in another video card would that allow me to span onto the other two or how would Windows treat those displays?

http://www.newegg.com/Product/Prod [...] rchInDesc=
 
Here's 3 cards that come with 4 DVI ports.