rename-file-and-buffer.el

;; Never understood why Emacs doesn't have this function.
;; http://steve.yegge.googlepages.com/my-dot-emacs-file
(defun rename-file-and-buffer (new-name)
  "Renames both current buffer and file it's visiting to NEW-NAME." (interactive "sNew name: ")
  (let ((name (buffer-name))
	(filename (buffer-file-name)))
    (if (not filename)
	(message "Buffer '%s' is not visiting a file!" name)
      (if (get-buffer new-name)
          (message "A buffer named '%s' already exists!" new-name)
	(progn (rename-file name new-name 1)
               (rename-buffer new-name)
               (set-visited-file-name new-name)
               (set-buffer-modified-p nil))))))