class Klass {
  private $vars = array(
    'foo' => 'foodefault',
    'bar' => 'bardefault'
  );

  function __set($property, $value) {
    if ( array_key_exists( $property, self::vars ) ) {
      self::vars($property) = $value;
    }
  }

  function __get($property) {
    if ( array_key_exists( $property, self::vars ) ) {
      return self::vars($property);
    } else {
      return false;
    }
  }
}