@ php at mikebird 

You can pass arguments to your constructor through your getInstance method, assuming you are running php5.

        public static function getInstance($params = null) {
            if (self::$objInstance == null) {
                $strClass = static::getClass();
                self::$objInstance = new $strClass($params);
            }
            return self::$objInstance;
        }

This would pass the params to your constructor. Love for php.