On Feb 25 President Barack Obama delivered his first address to a joint session of Congress. He detailed his plans to nurse the US economy, and by extension, the world economy, back to health. But some members of Congress didn't give his speech their full attention. Instead, they posted "tweets" from their Twitter accounts. "Aggie basketball game about to start on ESPN2 for those of you that aren't going to bother watching Pelosi smirk for the next hour," Twittered the Republican Joe Barton. Shortly afterwards a red-faced missive came from the same source: "Disregard that last tweet from a staffer." The same day, first reports of the crash of Turkish Airlines flight 1951 near Schiphol Airport arrived - via a Twitter user. Soon after, another user posted an image of the crash, which has since been viewed over 72,000 times. Twitter had arrived. The social networking service allows users to microblog from their mobile phone or computer to anyone who'll listen. It's been seized upon by celebrities, artists, corporations, politicians, news services and ordinary people as the new, hot tech product and a perfect way to reach a large group of people with a short and simple message. For the most ardent Twitterers, even the site's failings are a source of pleasure: the "fail whale", as the logo that appears when the site is overloaded has been dubbed, has its own fan club at www.failwhale.com as well as its own page on Facebook, which currently has more than 4,000 fans. But not everyone has fallen in love with Twitter. A day after Obama's speech, the comedian Jon Stewart, whose Comedy Central programme The Daily Show With Jon Stewart enjoys a youthful, Twitter-friendly demographic, expressed dismay at the frivolity of Twitter and the people who use it. "What are these Congresspeople doing?" he asked the American TV newsman Brian Williams. "They are in the middle of a historical address! It's like being at Kennedy's 'Ich bin ein Berliner' speech and they are down like this" - he mimed being hunched over a mobile phone punching in a tweet. "'I feel like I am cold '" He is not alone in questioning the benefits of Twitter. A host of voices, including psychologists, journalists and even internet gurus, have wondered whether Twitter is a revolution in how we communicate or a distraction best left to confused teenagers. An editorial on the former New Yorker editor Tina Brown's news site The Daily Beast summed up the feeling: "Somewhere along the internet highway, we fell under the spell that more communication is better communication. Sometimes more communication is just noise." Twitter first came to life at the South by Southwest music festival in Austin, Texas, in 2007. It was an immediate hit, used by attendees to find the best parties to go to. Its inventors, Biz Stone, 34, and Evan Williams, 36, won a SXSW award. On the face of it, they seemed like two typical Silicon Valley tech geeks. Except that Williams, who describes himself as a "farm boy from Nebraska who got lucky", is a major figure in online publishing. In 1999, he invented the term "blogger" and helped popularise the word "blog". (He sold his Blogger platform to Google in 2003.) He says he invented Twitter "for fun". Six million people currently use Twitter - puny compared to Facebook's 150 million users and minuscule when you consider the estimated 1.5 billion web users. However, Twitter's founders believe its audience will grow. It's certainly easy to use. Once you open an account, Twitter allows you to post text messages to the web. There is a 140 character limit on every posting - similar to sms texting on a phone - and you can "follow" other users, who also can follow you. It resembles Facebook's status updates (Facebook asks: what are you doing right now?) but everyone can see your posts and they can be loaded in real time. Inevitably, many users' posts tend to be mundane, fragmented accounts of what they got up to at the weekend. But many believe Twitter represents a powerful communication tool. President Obama is one. He is the service's most followed user (381,724 as of the weekend), and now his one-time technophobic rival John McCain is getting in on the act. "Yes, I am Twittering on my BlackBerry but not without a little help," read a recent post. Quite a turnaround for a politician who famously admitted he never used e-mail and whose aide once had to reassure the public: "John McCain is aware of the internet." It took the UK comedian Stephen Fry (the tweeter with the second most followers, 270,742) to introduce Middle England to the service. When he got stuck in a lift in BT's Telecom Tower in London last month, he posted a tweet which read "OK. This now mad. I am stuck in a lift on the 26th floor of Centre Point". His message, together with a picture taken from a mobile phone, made headlines across the UK. Other celebrities have embraced Twitter with gusto. The UK chat show host Jonathan Ross, a keen tweeter, promised his followers he would say the word "salad" during his Feb 9 Bafta speech (and did so after 45 minutes). The pop star Lily Allen - enjoying a No 1 album at the time - got in a heated disagreement with the gossip blogger Perez Hilton while on Twitter (she called him "jealous and bitter"), and then posted a picture of herself dressed as duck on to TwitPic, the photo service that can be linked to via tweets. Allen says she is "addicted to Twitter", posting up to 40 times a day while on tour. The basketball hero Shaquille O' Neal has declared himself a citizen of "Twitteronia" and has invited other citizens (or users) to approach him any time they feel like it. In the art world, Yoko Ono has Twittered a series of characteristically profound/meaningless posts ("We're all water in different containers. Someday we'll evaporate together"), while the New York conceptual artist An Xiao has used tweets as "a way to capture thoughts and share them". The author of Turn of the Century, Kurt Anderson - one of the medium's more thoughtful practitioners - has wondered aloud when the first Twitter novel will be published. Galleries such as London's Tate and New York's Moma have used Twitter to publicise events. America's troubled car manufacturers have zeroed in on Twitter as an effective means to build relationships with its customers. GM's Twitter account has 3,260 followers. Ford has gone one step further and last year appointed the marketing man Scott Monty as their "head of social media". Monty says Ford's strategy is "to humanise the brand by having real people interacting in communities online". His Ford Twitter posts have attracted 13,332 followers. "Twitter breaks down the notion of the typical corporate monolith," says Monty, "because it's one-on-one communication. It's a great way to communicate with customers, employees, shareholders, retirees. We used it in December when people still thought Ford was participating in the federal government's loan programme for the automotive industry. We made it clear via Twitter that it was just GM and Chrysler. Ford is still independent." For Monty, using Twitter and other forms of social networking in business is rapidly becoming essential for many big corporations. "You have to fish where the fish are. If your customers are using social media you have to use it," he says. "I believe that in a very short period of time companies not participating in social media will be the odd man out." Companies such as JetBlue, Starbucks, H&R Block, Popeye's Chicken and Home Depot (which all have Twitter accounts) sometimes also use "sentiment analysis" to monitor and understand what people are saying about their products on Twitter. Ford calls it "the conversation index". "We measure sentiment about Ford in a number of different areas relative to the competition - areas like quality and environmental impact," says Monty. "We compare how we rate with GM or Chrysler." While business has been quick to see the commercial benefits of Twitter, what has really excited its inventors is how the service has affected news gathering. During the Mumbai attacks, users trapped in the Oberoi Hotel posted messages describing the ongoing chaos; a Twitter user broke the news of the crash of US Airways Flight 1549 into the Hudson by posting a picture to TwitPic and then sending a tweet with a link to the picture that read: "There's a plane in the Hudson. I'm on the ferry going to pick up the people. Crazy." During the Australian bush fires, people used Twitter to guide each other through the inferno. For news agencies such as the BBC and CNN, Twitter users at the scene of a crash have become a kind of Everyman, providing eyewitness accounts of the unfolding drama. Yet some web insiders have expressed disquiet about the 140-character limitations of the service. Owen Thomas, the managing editor of the Silicon Valley blog Valleywag, questions whether Twitter is in fact a source for breaking news at all. "It is phones - cameras in cellphones - that is transforming news gathering, not Twitter," he says. "When you look at what you get in a news tweet, its usually a URL for a real news website." The internet data collector Hitwise seems to back up his view. It recently found that as much as 10 per cent of downstream traffic from Twitter - that's web links contained within messages - were to news and media websites. "As a journalist, I use it as a source for tips, not competition for news," says Thomas. Dr Judy Kuriansky, who broadcasts to millions on American TV and radio shows, says that posting what you are up to on Twitter is a way to "overcompensate if you feel you are a nobody". "You can do everything on Facebook that you can do on Twitter but Facebook is private," says Thomas. "The technical and emotional default of Twitter is to share everything. Everything must be a public dance. "Being private on Twitter is making yourself an outcast. I have been publicly scolded by strangers on Twitter for being private with my posts. That goes to a feeling of entitlement and neediness. Their behaviour has to be validated by you, other citizens of Twitteronia," he says. There is also universal doubt as to how Twitter can actually make money. And as the service expands, so do its costs. In most countries, Twitter pays to download tweets to your phone. "The fact that you can use it on your phone is crucial to Twitters' differentiation and also the most costly thing about it," Thomas says. Twitter Inc is currently estimated to be worth $250 million (Dh918m), and recently turned down a Facebook offer to buy it for $500 million (Dh1.8 billion) in cash and Facebook stock. Despite the rejection of Facebook's offer, industry insiders say Twitter's revenue strategies seem weak. They include charging companies for brand verification (assuring users that GM's Twitter is really from GM, for example) and for targeted prompts for users to join company feeds. "The only way Twitter is going to make money is someone buying them," says Thomas. But whatever their plans, Twitter must tread carefully, as Facebook discovered when users became enraged over what they saw as the company's plan to take control of their private information. "It's vital they manage the trust and privacy issue when they decide to monetise it," says Dave Brown of BT Innovate. "Google balanced the needs of customers and is making money; Facebook is struggling. "Twitter has to be careful because if you lose trust, it's gone forever." Twitter has plenty of competition. Tumblr, Facebook, Yammer, FriendFeed, Plaxo, Last.fm and LinkedIn have all joined what's been called "the social media arms race". Indeed, there are so many social media sites that now there is a new social media site that allows you to integrate all your other social media sites. If you tell Ping FM what you are doing right now, it can feed the answer to all your social networks. That way, everyone following you everywhere will know exactly what you are up to. Which is a good thing, right?