Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Cool Cousin - Shaking up the travel world with good old human connection
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
FriendsTonight - Meet new friends to join your friends, tonight
Bigtent - BigTent is a web-based organization and communication portal for groups.
Overnight - Book a last minute room with locals, in seconds.