Two weeks ago, a US Airways flight crash landed into the Hudson River in New York. All 150 passengers, as well as the five crew, survived. The first people to know about this miracle were not reporters in CNN, Reuters or the Associated Press. The first to know were among the six million members of Twitter, the latest social networking phenomenon to enter the mainstream.

A picture of the downed plane was posted on TwitPic, a photo application used with Twitter. Within 20 minutes, it had spread out into the web. Beating the main news organisations has put a renewed focus on Twitter. Having long been the ‘next big thing’ among early internet adopters, Twitter is about speed, brevity and immediacy.

It is a web page displaying a constant stream of status updates - and nothing else - from you and your friends to let each other know what you’re looking at, what you’re doing or what you’re thinking.

Unlike blogs, Facebook or Bebo, waffle and windiness are cut out: you are restricted to 140alph a-numeric characters (which is about 20t o 25 words) per entry. There are no annoying ‘Snowball Fight’ invitations or ‘Friends’ Quiz’ requests. The interaction page is simple. It is a screen-sized stream of status updates from people you choose to ‘follow’. The more people you follow, the more updates crowd into your stream.

Similarly, although photos can be posted using external applications (such as TwitPic), its core simplicity makes it very easy to check and update. Not everyone is happy with the emergence of Twitter. Some see it as yet another narcissistic forum to enable people to share details of their dull existence with the world.

‘‘How boring: celebrities sign up to Twitter to reveal the most mundane aspects of their lives,” ran a headline in the Daily Mail two weeks ago.

‘‘Since ‘twittering’ revolves around talking about yourself, it’s no surprise that it has been embraced by celebrities and politicians - but most of their posts would be worthy of the most tedious dinner-party bore,” wrote the paper’s entertainment journalists, Matt Sandy and Ian Gallagher. Britain’s Daily Telegraph has joined in the slagging.

‘‘Twittering is for twits with nothing better to do,” ran a headline on a recent scathing column.

‘‘Six million people may be at it but I’m not about to start tweeting,” wrote the paper’s Bryony Gordon. ‘‘And if one more person sends me an email or a text saying, ‘do you tweet?’ I will stamp on my mobile and replace it with two tin cans attached to a piece of string. I bloody well don’t tweet. I am a human, not a Looney Tunes cartoon character with a lisp.”

But in Ireland, some vocal critics of the website have changed their mind about it. One such critic was the blogger and founder of Blacknight Internet Solutions, Michele Neylon. In early 2007, he posted scathing critiques about Twitter on his blog, mneylon.com. Today, he uses the service constantly, and has contributed almost 9,000 updates.

‘‘I was originally very cynical about the entire thing,” said Neylon. ‘‘I thought: ‘do I really want to know about the boring minutiae of the daily lives of thousands of people’? But then it gained a critical mass. Once it reached that mass, it became the network to use. Now I use it to follow and interact, mostly for business.”

Neylon still has issues with the forum, but has accepted its usefulness.

‘‘It doesn’t matter whether you think it’s good or bad. Whether you approve of it or not. A lot of our competitors and clients are on there. It’s like [Microsoft] Windows. Like it or love it you have to be pragmatic about it.”

Blacknight now runs promotions on Twitter, offering cut-price domains for those it interacts with on the website. Several well-know entertainers, athletes and politicians have begun to embrace Twitter.

Among the most followed Twitter celebrities are Stephen Fry, John Cleese and Jonathan Ross. Recently, US president Barack Obama and British prime minister Gordon Brown - through his office - have begun Twittering, while cyclist Lance Armstrong and the ex rugby player Will Carling are also serial Tweeters.

In Ireland, few celebrities have caught on to the technology. The silver-medal winning Olympic boxer Kenny Egan is one exception, posting updates every day and interacting with several other Irish Twitterers.

Adoption in Ireland, while growing, is behind Britain or the US. Whereas American technology pundits Robert Scoble or Kevin Rose have 50,000 followers or more, few Irish Twitterers have amassed a following of more than 1,000 people.

Those who have breached that level include the marketer Krishna De (2,680), MaxRoam founder Pat Phelan (2,450) and online marketing consultant Damien Mulley (1,235).

One of the first people to use the service in Ireland in 2006 was the web developer and Dublin socialite, Fergal Breen.

‘‘The service has kept me informed about friends and colleagues,” he said. ‘‘It’s also provided insight into their interests and served as a gossip delivery mechanism. I also use it to get Lottery numbers and other micro-news items that would previously have been delivered as SMS Alerts from my mobile provider.”

Breen, who presents DigiBitz on FM104’s Juice show every Sunday, dismisses the criticism of skeptics such as the Daily Mail.

‘‘I’ve heard the criticism ,but it misses the point,” he said. ‘‘This is a lightweight, one liner social news delivery system.” Like Facebook, Bebo and MySpace, Twitter has a growing number of software applications to make interacting and tracking posts easier.

Whereas 2008 was all about Facebook applications, 2009 is becoming a race between Twitter and Apple’s App Store among application developers.

So far, Twitter applications range from the paranoid (such as UseQwitter.com, which shows who has stopped following you and when they stopped) to the frivolous (such asTwitOrFit.com, which allows you to rate people by how attractive their Twitter photos are).

The speed of Twitter’s emergence has caught some companies by surprise. 3 Ireland, which recently launched its own INQ social networking mobile phone, neglected to add Twitter to its range of built-in applications.

However, the service is still missing some key elements, said Fergal Breen.’ ‘I would Tweet more if they still provided SMS,” he said.

‘‘I would happily pay for the service and am very surprised they haven’t opted to generate revenue in thisway. My present phone is not Twitter friendly. If it was I would Tweet more frequently.”