It seems that almost every time I mention Meetup.com, I have to explain what it is. I’ve actually only known about it for a couple of years myself, but they’ve been around since 2002.
Last year, on the ten-year anniversary of 9/11, anyone that was a member of a group on Meetup received an email from Scott Heiferman, Co-Founder & CEO, explaining how Meetup came about.