|It is basically a fancy mouse. Some have various hot key type of features and can integrate with some popular applications. The better ones cost almost $500.|
Normally the screen size is of no matter, the pad size assumes it to be the screen size. This may cause issues with wide screen/ normal screen size and wide/normal pad size if they are mismatched.
Also depends on the OS. We has OS2 on two screens and used one screen for tools and one for drawing. The digitizer would move from screen to screen.
"Best Practices", Event viewer, host file, perfmon, antivirus, anti-spyware, Live CD's, backups, are in my top 10