yes is the simple answer.
there are a couple of things that you need.
obviously you need another screen. the same size and aspect ratio (4:3 etc) would be preferable for ease of use.
you also need a graphics card with dual monitor support and the right connections i.e. DVI or VGA etc. check your screen for what connections it has but the graphics card may come with adapters.
software plays an important part in this. nvidia's own software deals very well with a dual monitor setup and comes with a plethora of customisable options to best suit your needs.
last but not least, i would suggest that you install either multimon (free) or ultramon (post if you need links) both of these add a second taskbar to the 2nd monitor and only show the programs open on that screen. ultramon is far better than the multimon but is not free
i thinks thats everything.
post if you need any more info
