<?php

function _phptemplate_variables($hook, $vars = array()) { 
  if ($hook == 'node') {
    if ($vars['teaser']) {
      $vars['template_files][] = 'node-teaser';
      $vars['template_files][] = 'node-teaser-'. $vars['node]->type;
    }
  }
  return $vars;
}