I really like having the Ctrl and Caps Lock keys swapped on my keyboard. It makes using emacs just that much better. In the past, on my Linux boxes, I've had to write a little xmodmap script to do it. I just learned that Gnome now has an option to do this in the Keyboard Preferences dialog under Layout Options, Control Key Position. Sweet. And who says Gnome isn't for power users?
For windoze I usually find a regedit script with google, such as this one.