Airbnb Experiences - Airbnb expands beyond rentals — now hosting Experiences
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Airbnb Live There - Don’t go there. Live there.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
GetYourGuide - Get tickets to the most popular attractions while travelling
Bigtent - BigTent is a web-based organization and communication portal for groups.