LearnHub (formerly Nuuvo) relaunched recently as an interesting social learning and teaching space. Although it provides space for schools, it is particularly interesting for individual learners and teachers who can create communities and learn from each others. There are some basic tools for materials creation but most prominent are social features such as reputation tracking and making connections.

Teach and Learn online. | LearnHub This is a social learning network where people teach & learn online.

learnhub - TechCrunch Online education has been booming recently, with new entries coming from startups eduFire and the upcoming (though nebulous) Grockit, among others. One of the newest is LearnHub, a startup that launched last March that has undergone a major redesign as it vies for a top spot in this space