Multiple Screens

Does anyone work with multiple monitors for a single operating system? Sorry this may be ever so slightly off topic, but as I am trying to spec a new PC for movies, music and DVD conversion, I also realize that I would like to open and spread out multiple screens, websites etc across more than one monitor. Is this possible? What specs or additional switches or software would I need? Thank you.

I use mutiple screens for one of my courses at uni, we have a CRT as the main screen and a LCD one as the secondary screen. When I first saw the setup I just thought it was another example of the UNi spending money for the sake of it, but it actually comes in REALLY handy, especially when writing essays (with say websites as a reference), doing photoshop work, websites etc. As far as I know most video cards these days have what is required to use the two monitors. But just in case, the Uni is using GeForce4 Ti4200 cards in there PCs, runing WinXP Pro. And as far as I'm aware no other special hardware is used.

Yup, I do with my home rig, and sounds very close to the setup above. Primary is CRT, secondary is LCD, running WinXP on a GeForce 4 Ti4400. Most GeForce Ti and Radeon cards come with three outs: 1 VGA, 1 LCD (digital flat panel), and 1 TV (SVideo). Control of both monitors is handled by the GeForce drivers. It works great. Windows will span both monitors, even though they're at different resolutions. I haven't found any problem with it so far. I love being able to set-up encodes on one monitor while watching a movie on the second one. :)