I am off on my travels this week. My 17-year-old son has been left in charge of the house with strict instructions.

He has instructinos concerning parties and even stricter instructions to send me an SMS text message every day to reassure me that he is still alive.

SMS, the Short Message Service, is more commonly known as text messaging - the ability to transmit messages of up to 160 characters to and from a mobile phone, rather like a messaging pager.

So why has text messaging become so popular and what makes it such an attractive way to stay in touch? And how does it manage to bridge the generation gap so well?

Quite simply, the humble text message is almost painless. It does not cost much money so kids can afford it and, best of all, it is really easy to use. Anyone with a digital mobile phone can now send and receive short text messages. It is the ideal way to keep in contact when you cannot make or receive voice calls.

In February, an SOS text message from Rebecca Fyfe, 19, to her boyfriend 8,000 miles away in the UK launched the dramatic rescue of ten British tourists stranded on a storm-tossed outrigger off the coast of Bali.

Among those rescued were Shayne Howell, 29, from East-bourne and Marcus Whitney, 21, from Crowhurst, near Hastings.

All GSM (Global System for Mobile Communication) phones can receive text messages. The messages are stored in the phone's SIM (Subscriber Identity Module) card or on an internal memory chip and can be read by almost any type of mobile phone.

You do not even need a mobile phone to send a message. Anyone with internet access can go to one of the free SMS web sites and send as many messages as they like completely free of charge.

Start your online SMS experience by visiting the useful Genie web site and filling in the online registration form. Genie does not appear to send any junk mail to those who register and the site allows users both to send emails and to find up-to-date information on all kinds of mobile communications.

Lycos offers an excellent free SMS service. With Lycos, you can send text messages from any computer in the world to any UK mobile phone. Like Genie, it is free of charge and you can send as many messages as you wish.

Supporting their boasts about increased service levels, Orange has jumped on the SMS band-wagon but unfortunately the Big O offers only a paltry 30 free messages a month from their web site.

If everyone else can do it for nothing, why not Orange?

Text messaging is for all and offers an inexpensive way to keep in touch with friends and family, even when travelling abroad.

If you have not tried text messaging before, press the menu button on your phone and select the Messages option. Scroll until you find the Write Message option and select it. Key in your message using the keypad and access the Options menu to find a Send command. Fill in the target mobile telephone number and click to send the message.

It really is as simple as that.

www.genie.co.uk/public/
gmail/index.html www.lycos.co.uk
www.orange.co.uk