I was embedding some related links in a node and had a hard time getting it to be displayed after my custom text and images. The reason is that weight is set in links_related_nodeapi and is lighter than CCK fields. There is an noce solution for this inspired by http://www.lullabot.com/articles/great-pretender-making-your-data-act-field. Then it will be possible to reorder Related links in your node content output where you want.

/**
* Implementation of hook_content_extra_fields.
*/
function links_related_content_extra_fields() {
  $extras['links_related'] = array(
    'label' => t('Related links'),
    'description' => t('Releated links.'),
    'weight' => 100,
  );
  return $extras;
}