Another example of a temporary overlay map in emacs...

window-control.el

(defmacro repeater-map-more (keymaps &optional msg)
  "For complex maps in which multiple repeatable keys are attached to
functions."
  `(set-temporary-overlay-map
    (let ((map (make-sparse-keymap)))
      (loop
       for (repeat-key fun) in ,keymaps
       do (define-key map (vector repeat-key)
            `(lambda () (interactive)
	       (if ,msg
		   (message ,msg))
               (if (listp ',fun)
                   (apply (car ,fun) (cdr ,fun))
                 (,fun)))))
      map) t))

(defun jqt/continue-more (keymaps &optional msg)
  "Helper method for not much at the moment..."
  (if msg
      (message msg))
  (repeater-map-more keymaps msg))

(defun jqt/window-control ()
  "Creates a temporary overlay map for:
 - `f' switch to next window
 - `b' switch to previous window
 - `p' switch to previous buffer
 - `n' switch to next buffer
 - `j' switch to top jabber buffer
 - `s' switch to buffer from the minibuffer
 - `d' delete current window
 - `c' split window to compare last two buffers
 - `C' like `c' but split horizontally
 - `1' delete other windows
 - `2' split frame with one-third and two-third ratios
 - `3' split frame into equal thirds"
  (interactive)
  (jqt/continue-more
   '(;; switch windows
     (?f '(other-window 1))
     (?b '(other-window -1))
     ;; switch buffers
     (?p previous-buffer)
     (?n next-buffer)
     (?j jqt/switch-to-jabber-chat-buffer)
     (?s ido-switch-buffer)
     ;; resize windows
     (?d delete-window)
     (?c jqt/split-to-compare)
     (?C '(jqt/split-to-compare 1))
     (?1 delete-other-windows)
     (?2 jqt/two-third-it-up)
     (?3 jqt/split-window-into-three))
   "window-control map active..."))