Founded: 1999

Estimated users: 24 million

Addictiveness rating: 8

Formerly known as Facebox this was the first social networking site to be targeted exclusively at Europe and has 4.5 million users on the English version. It contains all of the usual features such as blogs, the ability to post videos and photos and users can organise themselves into groups known as 'clans'. It uses localisation technology so that users are shown targeted adverts and can carry out geographical searches for other members.