Quickly diff the changes made in the current buffer with its file

Update (23rd Jan 2010): Separated the key-assignment and  function definition.

A simple function to quickly do a diff of the current buffer contents with its underlying file. Very useful if the file has been changed outside (e.g., a log file).

;; Diff the current buffer with the file contents
(defun my-diff-current-buffer-with-disk ()
 "Compare the current buffer with it's disk file."
 (interactive)
 (diff-buffer-with-file (current-buffer)))
(global-set-key (kbd "C-c w") 'my-diff-current-buffer-with-disk)