Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Omegle - Omegle is one of the most popular online chat website allowing user to communicate with anyone without registration.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Chatrandom - Chatrandom provides medium to users for having chat at random with different users around the globe.
Bylde - Bylde is a SaaS platform you can use to Start, Manage and Grow your groups and communities.
LuckyCrush - Live random video chat