元ネタはこちら
http://www.macosxhints.com/article.php?story=20030711113941990

21.3.50.X で動く patch はこちら
diff -u osx-clipboard.el.orig osx-clipboard.el
--- osx-clipboard.el.origTue Jan 20 00:45:50 2004
+++ osx-clipboard.elTue Jan 20 00:33:44 2004
@@ -33,18 +33,14 @@
(defun osx-pbcopy ()
"copy the contents of the region into the os x clipboard."
(interactive)
- (if (region-exists-p)
- (call-process-region
- (region-beginning) (region-end) osx-pbcopy-cmd nil t t)
- (error "region not selected")))
+ (call-process-region
+ (region-beginning) (region-end) osx-pbcopy-cmd nil t t))

(defun osx-pbcut ()
"cut the contents of the region; put in os x clipboard."
(interactive)
- (if (region-exists-p)
- (call-process-region
- (region-beginning) (region-end) osx-pbcopy-cmd t t t)
- (error "region not selected")))
+ (call-process-region
+ (region-beginning) (region-end) osx-pbcopy-cmd t t t))

(define-key global-map "¥C-c¥M-v" 'osx-pbpaste)
(define-key global-map "¥C-c¥M-c" 'osx-pbcopy)