Little wordpress plugin to block some comments with crappy URLs

comment-url-filter.php

<?php
/*
 * Plugin Name: Comment URL filter
 * Description: Block some comments with crappy URLs
 */

function filter_handler( $approved , $commentdata )
{
  $url = $commentdata['comment_author_url'];

  //If the comment author URL contains these things... set it to spam
  if (strpos($url, "/docs.google.com/") !== false) $approved='spam';
  if (strpos($url, "/youtube.com/") !== false) $approved='spam';
  if (strpos($url, "/www.youtube.com/") !== false) $approved='spam';

  return $approved;
}

add_filter( 'pre_comment_approved' , 'filter_handler' , '99', 2 );
?>