swap-buffers

(defun swap-buffers ()
  "Swapping buffers in two windows"
  (interactive)
  (let ((current-w (frame-selected-window))
	(current-b (window-buffer (frame-selected-window)))
	(other-w (get-lru-window))
	(other-b (window-buffer (get-lru-window))))
    (if (not (one-window-p))
	(progn
	  (select-window current-w)
	  (switch-to-buffer other-b)
	  (select-window other-w)
	  (switch-to-buffer current-b)
	  ))))
(global-set-key (kbd "C-x \\") 'swap-buffers)