Change Drupal Theme Based On URL Path

$THEME_URLS = array(
 array('/admin','garland'), # Drupal already support admin theme anywho
 array('/users','fancy_user_theme'),
 array('/forum','forums_theme'),
 );
foreach ( $THEME_URLS as $info)
 if ( strpos($_SERVER['REQUEST_URI'],$info[0])===0)
  $conf['theme_default'] = $info[1];