OpenCirclez - Share local activities and events with friends nearby.
Google Groups - Google Groups allows you to create and participate in online forums and email-based groups with a rich experience for community conversations.
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
DownToMeet - DownToMeet is a platform to organize, find, and attend group events.
Mighty Networks - Mighty Networks enables entrepreneurs, organizations, and companies to create and grow a community-powered brand.
Zenly - Zenly is a GPS tracker to locate your friends in realtime.