I'm a big advocate of multiple screens: two is definitely better than one; after a while with two you start thinking you need a third; and if you go three you need 2 video cards so you may as well have four! What do I use four screens for?
- Far left: e-mail, reading PDFs of specifications etc
- Middle left: running version of whatever application I'm developing
- Middle right: my IDE, spread over two screens, with this screen being a full screen of source code (bliss :)
- Far right: the rest of my IDE, including server console, debugging tree, folder navigator etc