By Dan Whitworth
Newsbeat technology reporter
Twitter is run by co-founder and CEO Evan Williams (above)
New figures just out show that the number of people using Twitter in the UK has gone through the roof over the last year.
It's not just the public using the site either - celebrities like Barack Obama, Jonathan Ross and Russell Brand have all jumped on the bandwagon.
Market research company Nielsen Online says Twitter grew by 1,689% from February 2008 to February 2009.
That means there are now more than 1.78 million people signed on.
This time last year the social networking site only had 100,000 members.
The same figures, however, show Facebook is still far and away the leading social networking site, with 17.8 million users and steady, strong growth of 114%.