function prettysearch_url_inbound_alter(&$path, &$options, $original_path)
{
   if($path = 'pista'){
     $path = 'user/1';
   }
}

function prettysearch_url_outbound_alter(&$path, &$options, $original_path)
{
   if($path = 'user/1'){
     $path = 'pista';
   }
}