It seems like only yesterday that everyone was just learning about Twitter, and the correct name for the 140 character or less messages (sometimes referred to as Twits, Chirps and some that can't be repeated). It's come a long way from it's inital message. Paul Lamkin from Pocket-lint has more:

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.

For those who have a lot to say, Twitter has become the best way to get your message out (just ask Charlie Sheen who has just hired someone to handle his digital media exposure). Are you a Twitter user, and if so, who is your favorite person to follow?