Almost 40 years ago, Marshall McLuhan - known for the phrase The medium is the message - talked of media as extensions of ourselves. Goodness knows what he would make of mobile phones, which weren't part of his remote horizon. They are not so much extensions as parts of ourselves.
The mobile phone is the first interactive device that the vast majority of people (excluding the very old and very young) carry wherever they go. Many even keep them bedside for an early morning call. Yet the revolution has happened so fast we are only just beginning to alter our lifestyles to it. And in some cases, we haven't even started to.
Take the wrist watch. It is now redundant but hardly anyone realises it. Look around you. People with mobile phones still look at their watches if they want the time or the date. That is completely unnecessary now because mobiles have clocks and calendars with backlit screens for night viewing, and they can be updated remotely.
It remains to be seen whether this leads to a repeat of the slide-rule syndrome: no manufacturer of slide rules started making electronic calculators even though their business was about to be destroyed, and no maker of calculators had previously been in slide rules. Watchmakers, be warned.
Manufacturers of mobile phones are thinking a lot about functions they can put in phones and they have now reached a critical stage. Miniaturisation of the sets has just about reached the limits of usability. They can't be shrunk in size much more.
But the components within them will continue to shrink, leaving space for all sorts of new functions. Over the past few years, phones have absorbed MP3 players, blood pressure monitors, diaries, web browsers, emailing facilities, radios, clocks, games and thermometers. And they are about to incorporate cameras.
What next? Television may soon be thrown in (the screen is already there), as well as bar code scanners, location devices, multimedia messaging, TV consoles, telescopes, optical scanners and web-linked health checkers: anything that can be miniaturised.
The limiting factor is not the availability of gizmos but the infrastructure. The cross-network problems that plagued Wap may also prevent the much faster GPRS ("always on" to the web) from fulfiling its potential with the upcoming multimediamessaging service (MMS).
Unlike texting, MMS needs GPRS and so far it only works on three out of Britain's five networks. There is nothing lonelier than a medium without a message.
