This is a solution that has been bugging me ever since I set up my dual monitors at work. The default behavior of Windows XP is to NOT have the focus follow the mouse, which results in lots and lots of wasted clicks (time) just in switching focus between applications.
This guy’s solution fixed it for me. Thanks, guy!
Focus-follows-mouse
Believe it or not, Windows does support focus-follows-mouse, though there is no GUI configuration exposing it. Instead you must edit a registry key and then log out and back in for the change to become effective. You can use regedit to edit the key.
On Windows 2000, XP, or 2003, you need to change a binary-valued registry key:
HKEY_CURRENT_USERControl PanelDesktopUserPreferencesMask
This is a little-endian bitmask. For focus-follows-mouse, add the flag 0x1. For example, my XP SP2 laptop originally had a value of 9E 3E 05 80, which is 0x80053E9E. To activate focus-follows-mouse I changed to 0x80053E9F, or 9F 3E 05 80 in regedit.
According to http://www.winguides.com/registry/display.php/18/ you can also achieve raise-on-focus by adding the flag 0x40. I haven’t tested that as I don’t like raise-on-focus.
I haven’t tried the raise on focus thing yet, but I might!