Display an incrementing number on each post

The tweak below will let you display an incrementing number on each post, and implementing it is pretty simple. First, paste the following function into your functions.php file:

function updateNumbers() {
    global $wpdb;
    $querystr = "SELECT $wpdb->posts.* FROM $wpdb->posts WHERE $wpdb->posts.post_status = 'publish' AND $wpdb->posts.post_type = 'post' ";
    $pageposts = $wpdb->get_results($querystr, OBJECT);
    $counts = 0 ;
    if ($pageposts):
    foreach ($pageposts as $post):
    setup_postdata($post);
    $counts++;
    add_post_meta($post->ID, 'incr_number', $counts, true);
    update_post_meta($post->ID, 'incr_number', $counts);
    endforeach;
    endif;
}

add_action ( 'publish_post', 'updateNumbers' );
add_action ( 'deleted_post', 'updateNumbers' );
add_action ( 'edit_post', 'updateNumbers' );