ArcGIS doesn't seem to have much support for dual monitors. Maybe I'm missing something, but as far as I can tell you can't have the data view and layout view open at the same time on the two monitors, nor can you expand the map view to fill one monitor and have the toolbars and such on the other. How do you take advantage of dual monitors?
I've been using dual monitors for years with ArcGIS. A lot of the benefit is not so much in splitting the actual software over two monitors, but instead, to use it on one monitor and other programs on the 2nd monitor.
Here is my current setup.
Monitor 1: Outlook, Windows Explorer, ArcGIS Attribute Tables, MS Access, etc
Monitor 2: ArcGIS Data/Layout View, Firefox, etc
I tend to have more than one instance of ArcGIS running at a time, so I will sometimes split them between monitors so that I can easily see both for reference or copy layers between the two.
If you are using ArcGIS 10, you have the option of having the Catalog window docked in your data view. It is still possible to have that open as a separate program, and you could move that to the opposite window for easy access.
You can do something similar with ArcToolbox. Either have it docked, or undock and move to a different window.
The long and short of it is, you have to play around with different configurations to see what works the best for you. Don't think of just ArcGIS when you think of your dual monitor setup, but consider it as part of your overall software workflow.
I use dual monitors to be able to understand the GIS data better.
I have a personal concept that involves separating data from information.
When I see a point, line or polygon on a map, that is data to me but nothing more.
When I can understand what that data means, it becomes information. Maybe the point is a building and a non-residential one that was built in 1977 for example...
The way two monitors helps me to understand this is being able to visualize of the data in one screen like ArcMap, and information such as attribute tables or graphs in the other.
They're complementary and make it so I do not have to Alt+Tab through various windows for example.
Two monitors can increase my productivity and make me more efficient when completing various GIS tasks. Like an artist with a large drawing board.
With version 10, I am quite happy to detach my Table view and have it sitting in my other screen. Having 4 screens myself I tend to also have ArcCatalog open and on my next screen. You can detach your command window also. So there are many ways to use the separate screens.
I used to have the Identify, Catalog, Toolbox windows set to autohide on the right side of the main window - but I've now moved all 3 into their own window on the other screen. Now I can use them without them popping out over my map, and possibly hiding the area I was interested in.
I have tried to get the Search window out fo the main screen too, but every time I try ArcGIS crashes.