123: How do I "swap" two keys?

  In Emacs 19, you can swap two keys (or key sequences) by using the
  "keyboard-translate" function.  For example, to turn `C-h' into DEL and
  DEL to `C-h', use

        (keyboard-translate ?\C-h ?\C-?)  ; translate `C-h' to DEL
        (keyboard-translate ?\C-? ?\C-h)  ; translate DEL to `C-h'.

  The first key sequence of the pair after the function identifies what is
  produced by the keyboard; the second, what is matched for in the keymaps.

  Keyboard translations are not the same as key bindings in keymaps.  Emacs
  contains numerous keymaps that apply in different situations, but there
  is only one set of keyboard translations, and it applies to every
  character that Emacs reads from the terminal.  Keyboard translations take
  place at the lowest level of input processing; the keys that are looked
  up in keymaps contain the characters that result from keyboard
  translation.

  Also see "Keyboard Translations" in the on-line manual.