Learney - Knowledge aggregator for developers
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Multiplication Kingdom - Learn the times tables by playing and having fun in the Multiplication Kingdom (for kids and adults!)
Facebook Local - Discover places to go and events happening near you
Khan Academy - Khan Academy offers online tools to help students learn about a variety of important school subjects. Tools include videos, practice exercises, and materials for instructors. Read more about Khan Academy.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets