there is The Society in hartford, ct...they're a more broad BDSM group but they do have events catering to specific interests.
their next "Spanko Invasion" is june 4th.
http://thesocietyct.org/
i've been spanked on my thighs (the back of them and inner), and on my calves, and my hands.
i didn't enjoy any of it at all, which i suppose made them effective punishments - but they may become "hard limit" areas for me in the future.