The famous try their hardest to conceal themselves on this site, but the media still manage to find them. They've had gossip from Lily Allen declaring her singledom a few years ago to discovering who else Jennifer Thompson has been hanging around with after the Rooney scandal.

What is it?

Despite predictions that it would lose favour over time, the definitive social networking site Facebook has gone from strength to strength, and in July 2010 it hit the 500 million user mark.

Its success is in part due to the way it has adapted to the needs and demands of its customers, letting them connect with old an school friend, business colleagues, or people in their area. Facebookers can also share videos, web links, photographs or show their allegiance to their favourite celebrities and TV shows.

Now a new dimension has hit the site. 'Questions' brings search to the platform, allowing users to post their queries so Facebook's 500m strong network.

But what are the other websites that captivated our imaginations or are preparing for take-off in the UK market?