Apparently this is VERY possible now, and has nothing to do with whether you are using XP / Vista / 7 / 8. I did a quick search on Newegg just now and found a number of 2 port and even 4 port dual monitor KVM's. The number of ports translates to the number of computers you can have hooked up, and the "dual monitor" is self explanatory. The link below is for a 4 port dual monitor KVM that allows you to even connect and share audio and even USB devices with all 4 of the connected computers as well, which is a huge benefit. Obviously other resellers carry same or similar products and there were a number of different products listed on the Newegg site I searched. As of this date the 2 port models ranged from just under $100 to the mid-$100 range and the 4 ports ranged between around $200-$400, depending upon brand and features. I was impressed with the features of the IOGear model that I have included in the following URL. If you read far enough down into the page for this item, there is a very good description/example of how this device can be configured and used.
Hope this helps!
KVM Model: IOGEAR GCS1744 4-Port Dual View KVM Switch w/Audio and USB
URL:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817107454P.S. This is my first post in this forum. I came here because I have been using a 4 port, single monitor KVM setup, and use dual monitor on my primary computer only. I have always wished for a solution that would allow me to share dual monitors throughout all of my attached computers. On a whim today, I decided to Google search to see if anyone had finally come up with a dual monitor solution, and came across this forum post. Seeing a glimmer of hope, I did some more research and wanted to pass along my findings. Thanks for the initial post and replies that peaked my interested to do some more searching. I am really excited to find the above KVM -- it's going to be my next purchase fo sho (along with a couple more dual video cards for my other computers!).