Single-use keybindings?

[Eric Abrahamsen]

A few times I've found myself wanting the ability to set a single-use
keybinding: the next time the user hits "q" (or what have you), run this
command, then reset "q" to whatever it was before.

This feels hacky, obviously, but more importantly it feels like I'm
not using the right tools, or misusing what I've got. Has anyone else
wanted to do this? Any better solutions? Maybe I should be using a minor
mode that turns itself off after use, or...

Anyway, any thoughts would be much appreciation. Here's the function I
just wrote -- it pops to a certain buffer from wherever you are, and
when it gets there it rebinds "q" to pop back where you came from,
resetting "q" to it's original binding as it goes. It works, but I still
feel bad about it.

Eric

(defun ebdb-mua-in-ebdb-buffer ()
  "From an MUA, temporarily move point to the corresponding EBDB buffer.

All further operations will take place within the EBDB buffer as
per normal, with the exception that \"q\" will return point to
where it was in the MUA, rather than quitting the EBDB buffer."
  (interactive)
  (let* ((buf (get-buffer (ebdb-make-buffer-name)))
         (w-conf (current-window-configuration))
         (w-win (selected-window))
         (w-point (window-point))
         (e-win (or (get-buffer-window buf)
                    (ebdb-pop-up-window buf t (ebdb-make-buffer-name))))
         q-bind)
    (select-window e-win t)
    (setq q-bind (key-binding "q"))
    (local-set-key
     "q"
     (lambda ()
       (interactive)
       (local-set-key (kbd "q") q-bind)
       (when (window-live-p w-win)
         (set-window-configuration w-conf)
         (goto-char w-point))))))