Two years ago, Zoe Zahra, 21, a student from Bromley, had hardly heard of instant messaging (IM). Having seen friends from university drift away to cities across the country and beyond after graduation, messaging now proves essential for keeping tabs on the goings-on of her scattered crowd.

“They live in Leeds, Brighton, Portsmouth, Spain, Italy and America,” Zahra says. “It’s the cheapest way of staying in contact, especially with those who are abroad.” Daily messaging sessions spent sitting in front of her computer can last anywhere from 30 minutes to two hours. She is a convert to the net’s most immediate way of staying in touch.

Telephone, text and e-mail are the established heavyweights of modern telecommunications. By comparison, IM is an upstart, but it marks a sea change in the way we communicate and is challenging the supremacy of its older siblings. The research firm Forrester estimates that in its first five years, IM has grown a third faster than e-mail did in its infancy. Cash-strapped, time-rich youth drive the market, says Forrester, with 16- to 24-year-olds three times more likely to message than older users. Such is the popularity of messaging that American MTV’s Rock the Vote campaign, in an attempt to further political participation among the young, has developed a specially branded IM program that voters can use to discuss the forthcoming presidential election.

There are two significant draws: first, you always know when your friends are online because IM programs alert you to the presence of contacts (known as “buddies”). IM is like your own private party, where you invite who you choose — no more unheard messages left on answerphones, or e-mails fired hopefully into the ether. The second advantage is that, providing you have an internet connection, it’s free, whereas text messaging on mobile phones costs hard cash. With a broadband connection you can chat online for as long as you like, without worrying about bills.

Another attraction for the young is that they can perform the kind of multitasking that, face to face, or even on the phone, would be considered the height of bad form. In fact, lack of attention is a given. Messages plop into an on-screen window as fast as your buddies can type them, mirroring the flow of a face-to-face conversation, without the free-for-all anarchy of an unsecured chat room.

The thumb-culture generation, bred on a diet of multiple information feeds, thinks nothing of chatting to different people simultaneously, while surfing the web, listening to music and playing games. If this were a real-life party, they could mix themselves a drink and strut their stuff on the dancefloor, while gossiping with friends at the jukebox and checking out that cute-looking guy who’s just walked into the room.

“With e-mail, you don’t know how long it will take to be read,” Zahra says. “Things can be old news by then. With IM, you can take your time, say as much as you like and go into detail. And it costs nothing. I probably wouldn’t make as much of an effort without IM.”

Nielsen/NetRatings reports that MSN Messenger, by far Europe’s most popular IM application with a user base of 27m (nearly 8m in the UK), has overtaken Hotmail as the portal’s most popular service, although e-mail remains the most popular form of online communication.

While the no-cost factor appeals to a young audience, IM has far wider implications for friends of all ages who want to stay in touch. Much of the explosive growth has so far taken place in America. In the UK, the popularity of texting via mobile phone, particularly for short-term social planning of the “What shall we do tonight?” kind, has stolen much of IM’s thunder.

The rumbles are growing louder, however. Sitting down at a computer is no longer seen as the preserve of geeks — it is an integral part of young people’s lives — and messaging keeps them at a screen. MSN and Yahoo! Messenger users clock up three hours each month, compared with less than an hour on free webmail services, according to Nielsen. In an attempt to capitalise on the “stickiness” of IM, Yahoo! Messenger (uk.messenger.yahoo.com), with an audience of 1.2m in the UK, has recently relaunched, bundling fun distractions alongside the main program.

“In the past, Yahoo Messenger was fairly functional,” says Darren Laverty, senior marketing manager at Yahoo! UK and Ireland. The network now integrates some of the portal’s other charms: buddies can chat while listening to streamed radio from Yahoo!’s Launchcast music portal, exchange playlists and play arcade-style games against each other. The strategy appears to be working. “As we make messaging more involved and engaging, people are spending longer online,” says Laverty.

Lucy Pearce, 16, from Manchester, has been messaging for three years after friends switched her on to it. She chats sporadically the whole time she is online, usually surfing and playing games in addition to gossiping with schoolfriends. “I feel more comfortable messaging people than chatting on the phone. People can’t see your reactions, which makes it easier, in a way. You don’t get as nervous if you’ve got something important to say.”

Messaging has also been traditionally associated with contractions and visual symbols. This can create a shorthand that is all but impenetrable to the uninitiated. Emoticons, typified by the “:-)” smiley face, are now animated to roll about on the screen laughing; “audibles” — animated icons that make sounds or sentences — can be dropped into a conversation to mock or flirt; and avatars, or personal graphical representations, project an image to fellow users.

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