I would like a plugin that does what this Drupal module does: http://drupal.org/project/extlink
External Links is a small module used to differentiate between internal and external links. Using jQuery, it will find all external links on a page and add an external icon indicating it will take you offsite or a mail icon for mailto: links.
Configuration options:
* Apply icons to either mailto: or external links or both.
* Configure external links to open in a new window.
* A confirmation message when leaving the site (Section 508 compliance).
* Regular expression inclusion and exclusion of links considered external.