WIL I CU B4 2NITE may sound like the title of the newest pop song from the latest boy band to win the hearts of adolescent girls, but it's not. It's something much more straightforward - it's an example of the new abbreviated language used in hugely popular text messages which have won the hearts of the 1.5 million mobile phone users in Ireland.

While WAP (Wireless Application Protocol), the next generation of mobile phones may be the rage with the techies, for a certain section of society text messages, or SMS (Short Message Service), rule. Calling around to or even phoning friends is gone out the window. "I'll text you" is the newest way for young people to catch up on the latest gossip or to make arrangements to meet each other, all within the confines of a maximum 160 characters.

Text messages are so much more than the Esat Digifone television advert with the good-looking guy with the thick country accent bellowing "Kate it's me, the guy from the bar" wishing he'd sent a text message instead. They are now a way of life for many.

Eircell's recent advertising campaigns have been directed at business and consumer users. The average consumer is advised to say "L O 2 SUM1" with a text message, where business customers are urged to say "L O 2 A NEW BSNESS TOOL".

These messages seem to have had some impact as Eircell, which has one million customers, currently carries one million text messages daily, a 4,000 per cent increase on last year's 25,000 a day. According to Esat Digifone's latest figures, two million text messages are sent by their network every week between its 560,000 customers. "Especially younger people tend to use mobile phones for text messaging and there are certainly more text messages passed through Speakeasy, which has a younger profile," says Sarah Dempsey from Esat Digifone.

Cara Twohig from Eircell says that "in terms of lifestyle it's something they use". She likens the psychology behind it to passing notes in class. Teenagers often spend £10 a week communicating with their friends through text messages.

Emma Doran (22), a student in UCD, has a Ready to Go phone and says that the text messaging service is "practically the only thing I use on it. I text people all the time".

She mainly texts her boyfriend and sends text messages to some of her friends "the odd time" as it is cheaper than having a conversation. She sends "at least five or six a day" from her prepaid phone. Her boyfriend, who has a bill phone, counted up 130 SMS on just one phone bill, which works out at about four messages a day.

On Saturdays they usually "have a conversation through text messages" with her boyfriend's sister, who lives in Italy, as it's much cheaper than a phone call.

Mary O'Neill (22), from Kilkenny, is another text messager. "I probably send SMS more than I make phone calls simply because it's cheaper and it's a lot handier in a lot of ways," she says. (During the day it costs 80p per minute to make a phone call from a Ready To Go phone and a mere 10p to send a text message.) Also she finds that text messages are much handier for organising her social life. "If I send a text message at least someone is guaranteed to get it, whereas if you're ringing them in a pub they mightn't hear it."

Sarah Dempsey from Esat Digifone says that most users would send text messages such as "What time will you be there?". But business users find them useful if they are in a meeting and can't take a call. It's also good for getting an urgent message through to someone, she says.

Mary finds that with text messaging "punctuation goes out the window because it's too awkward to use". Ur for your and you're and 2 instead of to or two are the main abbreviations she uses. Navigating the increasingly smaller keypads can be irritating when typing a text message, unless you purchase a clip-on keyboard if you have an Ericsson phone. But there is a way around this and the 10p cost of sending a text message: send them from the Internet.

Eircell customers can send 30 free text messages per month from the Eircell website www.emerge.ie to other Eircell mobile phones. Esat Digifone says it will offer such a facility "shortly". However, anyone with Internet access can send text messages to Esat mobiles from www.mtnsms.com