Technically, Twitter wasn't launched officially until 15 July 2006, but as co-founder Jack Dorsey sent the first ever tweet five years ago today, on 21 March 2006, it seems only right to celebrate the micro-bloggers big anniversary now.

That tweet read "inviting coworkers" and wasn't perhaps as profound as the first ever tweet should have been, but it did kick-start a micro-blogging revolution.

As well as creating an exclusive group of twitterati (celebrities like Lady Ga Ga, Justin Bieber, Britney Spears and Stephen Fry) whose 140 character updates are read by millions worldwide, the platform has also been an incredibly powerful tool when it comes to citizen journalism and front-line reporting - think Iran, Egypt and the Hudson river aeroplane crash landing.

Recently Twitter said that it had set a record of 6,939 tweets per second immediately after the Japanese earthquake, and that an incredible 177 million tweets were sent during that day.

Today, the social network has more than 200 million members and there are more than a billion tweets sent every week. It is valued at £2.3 billion and there are more than 400 people working for it.

So Happy 5th Birthday Twitter, #manyhappyreturns.

Update: Wikipedia (which is never wrong) has the first ever tweet listed as "just setting up my twttr" from Dorsey. Either way, it was a pretty dull start to the micro-blogging adventure.