Verifique o wiki do Vim no wikia.com .
If you want to completely swap the Caps Lock and Escape keys, you have to replace the "Lock" on Caps Lock. Drop this file in your home directory:
! Swap caps lock and escape
remove Lock = Caps_Lock
keysym Escape = Caps_Lock
keysym Caps_Lock = Escape
add Lock = Caps_Lock
and call it ".speedswapper". Then open a terminal and type
$ xmodmap .speedswapper
The swapping lasts for the duration of the X session, so you can put it in a .xinitrc or similar startup file.
Existem alguns outros interessantes mapeamentos alternativos de ESC .