These days I spend most of my time working on machines running XP that have more than one monitor hooked upto them. XP’s support for multiple monitors is pretty good apart from one little niggle. You only get a toolbar on the primary window. To get around this I use a piece of software called Ultramon. It adds a toolbar per window and little buttons to the tops of windows that allow you to switch them across to other screens easily. There are more functions in Ultramon that I don’t use like screen saver and wallpaper functions but I don’t need them.
I’ve installed Ultramon on my Vista setup at home and whilst the toolbars work, they often get confused. Also the ‘swap window’ buttons don’t display (they are there but you can’t see them, especially if you are running the Aero interface).
Realsoft, the company behind Ultramon have come out with a beta release that has more Vista support. Something else to fiddle with 🙂