High-IQ Societies
    One High-IQ organization that has no entrance requirements is the Vitruvian Society.
    Individuals with IQs of 132 or above may join Mensa upon presentation of qualifying test results. Individuals with IQs of 137+ are eligible to join organizations such as TOPS (Top One Percent Society) and Intertel. An IQ of 141 and above will admit them to Colloquy. Those with IQs of 150+ qualify for membership in the Triple-Nine Society, the SesquIQ, the IQuadrivium Society and the One-in-a-Thousand (OATH) Society, those with IQs of 164 or above are potential candidates for the Prometheus Society and the Ultranet, and those rare specimens with IQs above 176 are welcomed into the Mega and Pi Societies.  There is even a Giga Society for the handful of people in the world (six) who qualify at the one-in-a-billion level. Needless to say, at the one-in-a-million level, the membership roster is somewhat exiguous. 
    Some of these organizations are also open to subscribers. Subscribers are not allowed to vote, but they may participate in the fascinating dialogues that take place within these societies.