>>411にならって直してみた

(defadvice yank (after yank-highlight-string activate)
(let ((ol (make-overlay (mark t) (point))))
(unwind-protect
(progn (overlay-put ol 'face 'highlight)
(sit-for 0.5))
(delete-overlay ol))))

(defadvice yank-pop (after yank-pop-highlight-string activate)
(when (eq last-command 'yank)
(let ((ol (make-overlay (mark t) (point))))
(unwind-protect
(progn (overlay-put ol 'face 'highlight)
(sit-for 0.5))
(delete-overlay ol)))))