Spelling on the Fly in Emacs

For some reason, I did not realize until yesterday that you can tell emacs to check your spelling on the fly in much the same way that modern word processors do. Simply run M-x flyspell-mode in the buffer you're working on. Emacs will then highlight each missed spelled word. You can then fix each mistake manually or use mouse-2 (the middle button) to bring up a list of suggested replacements. Also, if you run M-x flyspell-prog-mode instead while you're coding, emacs will check spelling only in comments and strings, but not your code.