Meetup groups are pretty successful, seems like. Meetup.com
There are all kinds of groups to join, book groups, board games, special interests, hobbies, etc.
I did a story on groups who meet regularly to play board games. Many of them were new to the area and made friends through meetup. A couple of the guys were surprising in their candor, saying they could play online games with other people, but it wasn't the same as face-to-face where you get to know the other guy, ask them about their lives, etc.