DocDroid - DocDroid is a service for sharing document and slides.
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
SlideShare - Discover, Share, and Present presentations and infographics with the world’s largest professional content sharing community.
Facebook Local - Discover places to go and events happening near you
SlideOnline - Share PPT presentations online easily with a free PowerPoint presentation sharing platform
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets