I just read some Terry Pratchett, and came across an Igor section. As we all know, Emacs can do everything, so here is what I ended up doing:

 (defun igor-reformat-buffer ()
   (let ((ruleth '("\\bsir\\b" "thur"
                   "ce" "the"
                   "ci" "thi"
                   "cy" "thy"
                   "ation" "athion"
                   "s" "th")))
     (while ruleth
       (goto-char (point-min))
       (while (re-search-forward (car ruleth) nil t)
           (replace-match (nth 1 ruleth) nil t))
         (setq ruleth (cddr ruleth)))
       (remove-text-properties (point-min) (point-max) '(personality)))) 

For those fans of loop, this could also be written as:

(defun igor-reformat-buffer ()
  (let ((ruleth '("\\bsir\\b" "thur"
                  "ce"        "the"
                  "ci"        "thi"
                  "cy"        "thy"
                  "ation"     "athion"
                  "s"         "th")))
    (loop for (word sub) on ruleth by #'cddr do ; destructure `ruleth'
          (goto-char (point-min))
          (loop while (re-search-forward word nil t) do
                (replace-match sub nil t)))
    (remove-text-properties (point-min) (point-max) '(personality))))

Anyhow, on with the show.

 (defun igor-tetht (thtring)
   (interactive "sText: ")
     (insert thtring) (igor-reformat-buffer) (message (buffer-string)))) 

 (defun erc-igor-output (thtring)
     (insert thtring)
     (setq str (buffer-string))))

 (add-hook 'erc-insert-modify-hook 'igor-reformat-buffer)
 ; And for those very extreme:
 (add-hook 'erc-send-pre-hook 'erc-igor-output)

The replace-match code does have problems with text-properties, that’s why I had to put the remove-text-properties call in there to get emacspeak to behave nice again. Any ideas on that? Anyway, it’s fun, and ViaVoice seems to pretty nicely pronounce this :)

Here is an example of what terrible things will happen if you do this:

 <mihtjel> I'm thure I've heard the thoundtrack on TV thometime..
 <Joy> i'm wondering if the movie ith worth watching
 <mihtjel> dunno
 <Robot101> Joy: yeth, it'th good.
 <broonie_laptop> Joy: It ith.
 <mihtjel> Robot101: What kind of movie ith it?
 <Robot101> mihtjel: a tom hankth movie =)
 <mihtjel> ah.. then ;)
 <Robot101> it'th a thob thtory to thome extent
 <Robot101> but it hath a thpooky athpect

MarioLang, ERC