http://greatnonprofits.org/reviews/issues/scitech/_/
FIRST is listed here, with some thoughtful "elevator pitches." You know you've been in FIRST too long when you recognize a lot of those posting.
There are some interesting small local groups.
There are also some groups I wouldn't have put in the "Science and Technology" category, but maybe there is something I am not seeing.
It's another one of these "vote for me" popularity contests.