Hmmm, I always thought you needed one of these DualHead2Go things from Matrox... (
Amazon Link) What makes the Matrox so much more expensive than the one that you have just linked?
Looking at their compatibility page (for the Matrox) they list a Max Resolution of 2048x768
(2x 1024x768) for my particular Macbook. I don't think that is right. I should be able to run two external monitors at 1600x900 from the 9600M, right? I thought it was a pretty capable card. Maybe that is just the limitations of the Matrox.
Have you used the device you linked me to push video greater than 2x 1024x768?