This is a PHP/MySQL/AJAX Rating Script, that uses thumb graphics to provide a thumbs up/thumbs down rating system. Easy to install. Just set the db variables in the config.php file, and you're good to go. Even comes with page to set up the necessary MySQL tables you will need to get the system working.

This system records ratings, and counts by 1 up or down for the ratings, it also using ip to help prevent multiple votes.