Edmodo - Secure Social Learning Network for Teachers and Students.
ePals is the social network optimized for K-12 learning. Over half a million classrooms in 200 countries and territories have joined the ePals Global Community.
Pinterest is a Virtual Pinboard. There are a lot of education ideas shared on this site!
Schoology is a learning management system (LMS) and social network that makes it easy to create and share academic content.
Kidblog's simple, yet powerful tools allow students to publish posts and participate in discussions within a secure classroom blogging community. Teachers maintain complete control over student blogs.
Unlike other news sites for kids, TeenTribune and TweenTribune are easy to use, updated daily and allow teens and tweens to participate in so many ways.
Diigo - Web Highlighter and Sticky Notes, Online Bookmarking and Sharing...
Diigo is a powerful research tool and a knowledge-sharing community.