Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
klaep - music collaboration - klaep is a social music collaboration network for musicians
Event Hunt - Startups and Tech Events Curated By Locals
Madsounds - It’s like Discover Weekly, but daily.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
MisterJack - Make and share playlists