The button mod I made does include the file pliggit.php, which you could use as just a voting link. Example:
http://mydomain.com/pliggit.php?url=...rgetdomain.com
When clicking on that link, a vote would be recorded if the story url already existed in the database (if not they would be re-directed to the submit page). If you have anonymous voting enabled, then a vote will be registered without the user needing to be logged in. I'm sure you could modify it quite easily to suit your particular requirements.
