Public - Group chats.
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
chitchat - Chat Room with Selfies and Pagers (yes, pagers!)
Event Hunt - Startups and Tech Events Curated By Locals
Vurb - A new way to find, plan, and do – all in one place
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets