Curriculumbits.com offer free online access to a growing range of interactive multimedia e-learning teaching resources. The online teaching resource library contains educational games, quizzes, animations and videos in a variety of subjects at key stage 3 and 4 of the UK National Curriculum.
I've spent the last day and a half testing it out, and so I've had the opportunity to use nearly every feature of the service. If you were to ask me how to best describe it, I'd say it is like Twitter, Facebook, Skype, and Gmail merged together and formed one, super social, Omni-beast of a website. The interface is elegant and beautiful, the features are easy to use, and you can "Circle" up with as many people as you want. However, it isn't without its flaws.