(defvar prev-window (selected-window)
  "Holds the previous window which was selected before a switch
  using other-window-repeat.")

;; a better command to be bound to C-x o
(defun other-window-repeat (COUNT &optional no-repeat)
  "Calls other-window.  If a multiple key sequence was used to
  call this then the last key can be used on its own to repeat
  this, like kmacro-call-macro."
  (interactive "p")
  (let ((repeat-key (and (null no-repeat)
                         (> (length (this-single-command-keys)) 1)
                         last-input-event))
        repeat-key-str
        (nxt t))
    ;; save current window
    (setq prev-window (selected-window))
    (other-window COUNT)
    (when repeat-key
      (setq repeat-key-str (format-kbd-macro (vector repeat-key) nil)))
    (while repeat-key
      (unless (current-message)
        (message "(Type %s to keep cycling)"
                 repeat-key-str))
      (if (equal repeat-key (read-event))
          (progn
            (clear-this-command-keys t)
            (other-window COUNT)
            ;; if we cycle all the way to the same window, set prev-window to
            ;; next window, then if we continue to cycle set it back again
            (when (eq prev-window (selected-window))
              (setq prev-window (if nxt
                                    (next-window)
                                  (previous-window)))
              (setq nxt (not nxt)))
            (setq last-input-event nil))
        (setq repeat-key nil)))
    (when last-input-event
      (clear-this-command-keys t)
      (setq unread-command-events (list last-input-event)))))
(global-set-key (kbd "C-x o") 'other-window-repeat)

(defun switch-prev-window ()
  "Switchs back to previous window that was selected before last
call to other-window-repeat or switch-prev-window."
  (interactive)
  (when (or (eq prev-window (selected-window))
            (not (window-live-p prev-window)))
    ;; previous window is best guess
    (setq prev-window (previous-window)))
  (let ((wind prev-window))
    (setq prev-window (selected-window))
    (select-window wind)))
(global-set-key (kbd "M-'") 'switch-prev-window)