`I want it and I want it now" is the phrase most frequently heard by retailers in relation to the new Nokia 8810 mobile phone. There is a fetish about this phone that has never been apparent before with buyers of mobiles. It's not just that it's the phone-of-choice for so many supermodels and pop stars, the secret according to Nokia's breathless marketing people is in the design: "One look, one touch, and you know you want it. And when you see all it can do, you'll know you need it" runs the blurb for the 8810, a phone that is now so popular with well-heeled, hands-permanently-to-their ear types, that the factory which makes them in Britain is now on a 24-hour-a-day production cycle, just to satisfy demand in the run-up to Christmas.

The designer of the phone, Frank Nuovo, had only one thing in mind when drawing up the blueprint. He wanted people to instinctively reach out and say "I like this" in the same way they do with a fine watch or a fountain pen. One of the chrome-wrapped phone's biggest selling points is its size - or rather, lack of it. Weighing in at just 118 grams and small enough to fit in your shirt pocket, it's as micro as they come. The hi-tech features help also. There's call management and wireless data connectivity for emailing, faxing and Web surfing.

At £850, it sure ain't cheap but the very fact that people are treating it as an "ultimate object of desire" says a lot about the ubiquity of the mobile phone (regardless of whether it costs £15 or £850). It has gone from being a luxury item to close on an indispensable one. Around 300 million people worldwide use mobiles and for ill or good they have revolutionised telecommunications. There have been some scare stories in the past about mobiles causing brain damage but in the rush to embrace the new, light and convenient technology these have been ridiculed as "urban myth". Not any more. Over £40 million is now being spent on major research studies around the world investigating possible health risks from over-use of mobiles. Among the studies is one by the World Health Organisation which is surveying in eight different countries to compare the incidence of brain tumours in those who use mobiles and those who don't.

The phones work by receiving micro "radio" waves from the nearest possible base camp. It is the rate at which these microwaves are absorbed by the heads of users which is the focus of the current research. Even though the microwaves from a mobile are set at such a limit that they are 50 times lower than those which might produce tissue damage (in the form of "tissue warming"), the question now being posited is does even the smallest amount of microwave radiation contain enough power to "warm" or cause tissue damage in the brain.

As far back as 1993, an American woman whose husband was a frequent mobile phone user and later died of a brain tumour sued a mobile phone company. She was unsuccessful, as all subsequent attempts have been. The subject got an airing again recently when Richard Branson wondered if the heavy use of mobiles had contributed to the death from a brain tumour of a friend, who had used them "all the time" for a period of 10 years. People's fears have been advanced due to publication of figures in Britain last year which showed a steady increase in the amount of brain tumours in the country over the last 10 years - the period in which mobile phone use has become prevalent. The increase, though, was found mainly in the 70 and 80-year-olds and has been put down to the greater use of scanning equipment in hospitals, according to the British Cancer Research Campaign.

Whatever about brain tumours, research carried out by Dr Alan Preece of the Bristol Royal Infirmary earlier this year suggested that mobile phone use might have an effect on mental skills. Volunteers who wore low-power microwave transmitters (which aped the effects of mobile phones) attached to their heads for 30 continuous minutes performed less well than expected on psychological tests to measure memory, reaction time and spatial awareness. A subsequent Swedish study found a correlation between the amount of time spent using a mobile and the incidence and severity of headaches, burning sensations and fatigue. However, speaking about his research, Preece said that the risk of short-term memory loss was not necessarily linked to the thermal effect of microwaves and that there is still no "scientific consensus" about possible health risks. Despite the lack of any conclusive proof, people are guarding against what they perceive to be a health threat through the increased use of hands-free ear-pieces, which allow you to talk and hear on your mobile via an ear-piece, without the phone being anywhere near your head. Ear-pieces to fit different models of mobiles are available in all mobile phone stockists, at prices from £30 to £60. The only drawback to them is that you look like you're talking animatedly to yourself when you use one.

There are also now protective sheaths (sound familiar?) available for mobile users. These fit around your handset and can absorb over 80 per cent of the radiation generated by the phone. These "mobile condoms" are available for £35 from a British company called Microshield, which has a mail order telephone number in the UK: 00 44 0181 363 3333. Safe talk - it's the only way to have social intercourse these days.