Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
DocSlide - DocSlide is an online document and knowledge sharing platform.
Event Hunt - Startups and Tech Events Curated By Locals
SlideShare - Discover, Share, and Present presentations and infographics with the world’s largest professional content sharing community.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Scribd - Unlimited books, audiobooks & comics. Unparalleled discovery. Any device. $8.99/month