I've had a lot of success with the CouchSurfers community. It's a travel oriented site, but they also promote meetups for the people living in a city so as to f

I've had a lot of success with the CouchSurfers community. It's a travel oriented site, but they also promote meetups for the people living in a city so as to form a tighter, most trusting community. When you throw travel-wise tourists, friendly city ambassadors, and generally open-minded go-out-and-tackle-the-world style people together in a room and have them share stories or plan events it gets crazy and amazing really, really quickly.