Another way is to add automaticaly all links to CODE tag on topics and posts

Open: /admin/sources/classes/bbcode/custom/defaults.php


FIND:
Code: 
return "<a href='{$option}' class='bbc_url' title='{$_title}'{$rel}>{$content}</a>";
REPLACE WITH:
Code: 
return "<pre class='prettyprint'>{$option}</pre>";

Have fun