Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Bunches - Start and discover free or paid group chats about anything
Event Hunt - Startups and Tech Events Curated By Locals
nocnoc - Instant group chat invite via link
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Reboard - Revolutionary multitasking iOS keyboard