Here is how they describe themselves:
Meetup is the world's largest network of local groups. Meetup makes it easy for anyone to organize a local group or find one of the thousands already meeting up face-to-face. More than 2,000 groups get together in local communities each day, each one with the goal of improving themselves or their communities.
Meetup's mission is to revitalize local community and help people around the world self-organize. Meetup believes that people can change their personal world, or the whole world, by organizing themselves into groups that are powerful enough to make a difference.
I recently moved and this has been a great way to get out into the community and meet some great people. Check it out and see what is going on in your area!
http://www.meetup.com/
