Random US phone number. (10 digits)

    Example::

        >>> rand_phone()
        (306)-746-6690

def rand_phone():
    """Random US phone number. (10 digits)

    Example::

        >>> rand_phone()
        (306)-746-6690
    """
    return "(%s)-%s-%s" % (rand_str(3, string.digits),
                           rand_str(3, string.digits),
                           rand_str(3, string.digits))