Wildcard - Discover, connect and meet people at communities
Learney - Knowledge aggregator for developers
Shapr - A completely free way to build your professional network.
Multiplication Kingdom - Learn the times tables by playing and having fun in the Multiplication Kingdom (for kids and adults!)
LetsLunch - Do more with your lunch hour. Meet new people.
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.