I do not know how many people this will be useful for but instead of forking out for one of the matrox triple head to go things (they are devices that take 3 monitors and stitch them together to make one ultra widescreen one) some people made a software equivalent which I stumbled upon just as I resigned myself to it not being possible unless I had odd hardware.
Now I only mention this as nvidia drivers are only capable of stitching two monitors together (which is useless most of the time as crosshairs are in the gap in the middle or right at the edge of the monitor) meaning that games which do not support multiple monitors by default i.e. about 95% of them can in some way use them. You can also do stuff like drop colour to 16bit on the side monitors to boost performance.
http://www.kegetys.net/SoftTH/

Another site that may be of interest if you go this route (or have a widescreen monitor):
http://www.widescreengamingforum.com/wiki/...x.php/Main_Page

Oh and omegadrivers (a set of custom drivers that frequently works better than the official, not to mention laptops that usually see perhaps 2 updates ever) have got back and did some nvidia stuff recently:
http://www.omegadrivers.net/