BARACK Obama is doing it. So are Britney Spears, Arnold Schwarzenegger, John Cleese and Stephen Fry.

They are Twitters, the latest social networking craze that is rapidly gathering pace across the internet.

It's a form of micro-blogging, sending short messages – or Tweets – to update friends, family and work colleagues on your latest activities.

"I'm interested in what others are up to," says Martin Wright, a 36-year-old software tester and organiser of the Nottingham Twestival, a gathering of Twitters at The Castle Pub opposite Nottingham Castle tomorrow night.

"I follow lots of people with similar interests and it's a great way to find out about news stories that are relevant to me."

The event is part of a worldwide Twestival that will find Twitters gathering in more than 175 cities around the world to swap ideas and discuss their experiences.

Martin said: "The meet-up is a great way to continue conversation."

Adam Bird, a 36-year-old managing director, will also be there.

"People have this idea that social networking is replacing face-to-face networking but it's not true, it just extends it."

Twitters send updates via computers or mobile phones. Each message is a maximum of 140 characters. They can also link to pictures or website stories they think may be of interest to their 'followers'.

"It's where the internet comes and finds you rather than you having to go out and find it," said Adam.

You can choose who to follow after which their updates will appear on your Twitter page.

Stephen Fry is the most popular Twitter with more than 98,000 followers. Recently when the actor/writer/presenter found himself stuck in a lift he sent a Tweet with a photo showing his predicament.

" I thought the whole 'Fry stuck in a lift' story was ridiculously over-inflated and annoying," says Mike Atkinson, 46, an IT consultant from The Park who joined Twitter in 2006.

"It was yet another case of the medium trumping the message (if this had happened anywhere else but on Twitter, no-one would have given a stuff).

"The same goes for the whole 'airplane crash landing in the Hudson' story, which first broke on Twitter. I found the whole 'Woo for Twitter, we're really important now!' reaction to be a distasteful skewing of priorities."

He added: "I signed up when the first ripples of blog-buzz were starting to circulate. At the time, it was seen as a cute little 'creative project', the idea being to respond literally to the question 'What are you doing?'. It also felt like a chance for old-school first-wave bloggers like myself to go back to basics – simple, short, hit-and-run pieces rather than the carefully crafted 'gimme a book deal!' mini-essays that had started to dominate the world of blogging.

"And for a natural waffler such as myself, the imposed 140-characted brevity definitely appealed.

"What I enjoy most of all is the social interactivity. What I dislike most of all is the sudden influx of people taking it Very Very Seriously Indeed, and trying to build reputations on the back of it. For me, Twitter is a sweet little time-waster, requiring little effort – as Charlie Brooker said in the Guardian on Monday, it's the online equivalent of popping bubble wrap.

"My other pet hates are people using their personal Twitter streams as duplicate RSS feeds (if I want to read your new blog post, I'll subscribe to your feed), and people sucking up to celebrities in the hope that the celeb will validate their existences by replying to them (try entering @stephenfry into search.twitter.com – it's a carnival of up-suckery).

"I only follow as many people's Twitter feeds as I can reasonably keep up with – this hovers between about 50 and 60 – and I show no mercy in unfollowing people whose Tweets aren't totally up my street, no matter how nice the person behind them might be."

Other celebrity Twitters include Russell Brand, Jonathan Ross, Phillip Schofield, Demi Moore and Ashton Kutcher, Yoko Ono, Jamie Oliver, Alan Carr, Al Gore and William Shatner.

Martin said : "Philip Schofield is very entertaining and it takes me right back to my youth."

Find out more about the event, which will raise money for charity: water, at twitter.com/nottstwestival

SIMON WILSON

How to Twitter Log on for free to twitter.com and click on Join The Conversation. Enter your full name and e-mail address, then choose a Twitter name for yourself. You can use you full name or a nickname – Jonathan Ross uses "Wossy". Upload a photo of yourself and off you go.

Veteran Twitter Mike Atkinson chooses his favourite Tweets:

Have spent the day discussing boys names. So far we have ruled out Trenchard, Mungo, Septimus, Caractacus and Ian. - @rachiesparrow

I just got struck off the 'followed' list by someone who apparently follows 19,913 people. I bored a spammer! - @swisstoni (Nottm blogger)

Top tips on public speaking: don't start a 3 minute speech with "2000 years ago..." - @alexfoster (Nottm city councilor)

It's typical that I found out it was snowing outside via Facebook and Twitter rather than by opening the curtains. - @willhowells

Thinking "we might make a move" may well be the most beautiful words in the english language. Yes, being a misanthrope, and ok with that. - @annapickard

The posh school mails parents that it's "closed due to inclement weather conditions". The local school relies on the mums' mobile network. - @goldfinsch

Woman on tube in killer heels, carrying a portable guillotine, some kitchen roll and four bananas. - @megp...

... @ megp - can you tell her to hurry up, she is late for our appointment. - @mrangry