//For Donncha's Sitewide Tags plugin: Populate tags blog with all posts made before the plugin was added
$posts = $wpdb->get_col( "SELECT ID FROM $wpdb->posts WHERE post_status = 'publish'" );
if ( !empty($posts) ) {
    foreach ( $posts as $post ) {
        $post_id = $post['ID'];
        if($post_id != 1 && $post_id != 2)
            sitewide_tags_post($post_id, get_post($post_id));
    }
}