Special Report on Electronic Gifts: Mobile phones aimed at the popular market: The latest offers may look tempting but, warns Steve Homer, the cost of staying in touch may be higher than you first think

THERE ARE three 'mobile' telephone services that you can use while out and about, aimed at ordinary consumers. The standard cellular operators, Cellnet and Vodafone, which now provide low usage schemes called Lifetime and Lowcall, are joined by Rabbit, a sort of hybrid between the mobile phone, the callbox and the domestic cordless phone.

The two low-use schemes from the cellular operators are appealing, but watch out: your bills may be much higher than you expect.

The two cellular services are sold by 'service providers'. Signing on to Lifetime or Low Call can be free and the monthly service charge may only be pounds 15 instead of pounds 30 for 'normal' cellular services but the cost of calls can be very high indeed.

A typical peak rate call is around 60p per minute - the same as calling the United States from your home phone. In fact the cellular companies admit that if you make more than one short call at peak times per day you would be better off with the conventional cellular tariffs. Two phones have been specially launched for these low-use schemes. Motorola's 'Personal Phone' is a very easy-to-use model, which costs pounds 250. Sony's offering, while more expensive at pounds 325, is exquisite. It is tiny, beautifully made and well designed, but is more complicated than the Motorola model.

So where does this leave Rabbit? Well, it could be a good alternative if you were already thinking about buying a cordless phone. Rabbit uses digital signalling between your domestic base station, which plugs into the telephone socket, and the handset.

Rabbit's adverts claim you 'can make and receive calls within a 200-metre-radius' and that 'everything is clearer than a bell'. That is somewhat optimistic. For example, I experience some break-up on the signal in my bathroom - less than 15 metres from my base station - although the phone works fine in the rest of the flat. The phone and base station cost pounds 200.

For pounds 7 a month you can use your Rabbit phone to make outgoing calls at roughly 50 per cent more than phone box prices in the High Street or wherever you see the Rabbit sign. Eventually Rabbit plans to have all the leading shopping areas covered but there are certainly plenty of places where there is still only very limited coverage.

The great advantage the cellular offerings have over Rabbit is that people can call you. Rabbit's way of getting over this is by using a pager (cost pounds 57.50) and a voice messaging service. You give your friends and business colleagues your messaging number, they ring in, leave a message, and your pager is automatically activated. Then you simply dial in and collect your messages. At an extra pounds 6.50 per month, this seems quite good value.

The disadvantage with the pager is that if you are out of pager range, on the Underground for example, you will not know you have missed a call. Both Cellnet and Vodafone have automatic callback if you are out of range. Callers leave you a voice message which is then replayed once your phone is back on the service. Very useful, but watch out: it could be very expensive if you collect your calls at peak-rate times, as you pay for the calls delivering the stored messages.

In case you are not confused enough already, another system designed for the consumer market called Personal Communications Network (PCN) which should be a lot cheaper than the cellular service, will be launched next year. However, PCN will only be available in the South-east for the first year or two and pricing details are still not available. Several other mobile services are also promised in the next 12 months or so.

Where does this leave the poor consumer. Rabbit is an interesting option if there are enough public base stations in your area. The cellular systems offer a far more flexible service but at a much higher cost and they cannot be used with domestic base stations.

You might, of course, decide to wait for the cheaper services that are bound to be developed. The only answer is to do the sums carefully, think how much time you are likely to speak on the phone and double it because one thing is certain, you will soon discover it is very, very useful and very satisfying always being in touch.