Making Windows Usable

If you ever have to use Windows, and are accustomed to "focus follows mouse" as I am, you might find this description useful.

I'm citing the important part here, to let me find it more easily:

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.
[...]
you need to change a binary-valued registry key:
HKEY_CURRENT_USER\Control Panel\Desktop\UserPreferencesMask
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.

Helped me a lot on a Vista machine yesterday. Don't forget to log out and back in again after the change.