Can a picture tell a thousand words?

The the first mobile phones that can send pictures have arrived. But are they any good? And, more important, which network should you use them on?

It's easy to imagine when you'd want to send a picture from your mobile phone to another one. Viewing a house, a baby's first steps, a party, a location... the possibilities are everywhere. Which makes it interesting that two of the five UK mobile networks have chosen to launch "multimedia messaging service" (MMS), which will inevitably come to be known as "picture messaging", although you can also add text and sounds to a picture (or just leave the picture out, if you'd rather). The two are T-Mobile and Orange; the phones which fulfil this functionality are, to begin with, the Sony Ericsson T68i and the Nokia 7650.

Choices, choices. Which operator? Which phone? The first is easier to answer than the second, so let's get it out of the way, as well as finding out what's holding the other three up. According to the research firm Ovum, by 2007 British mobile users will send more than 35 billion multimedia messages, and the market will be worth more than £3bn. Then again, I recall forecasts of theirs about how we'd all now have broadband and work for dot.coms. This year we'll send about 14 billion text messages, in a market that's saturated. I think Ovum are overestimating, but phone companies like the numbers, so they're getting on with offering MMS. So let's not hold them up.

T-Mobile (formerly One2One) has been billboarding London and other cities with pictures of a baby, as an example of the moment that you'll want to capture and forward. Yes, you think: that's the picture of a baby, and you'll send it to all your friends' compatible mobile phones. (Sure, your thoughts aren't that coherent after a baby arrives – but this is advertising.)

So there you are in the maternity ward. With T-Mobile, all you'll have had to do is sign up ahead of time for a picture messaging bundle costing £20 per month, which allows you to send or receive a total of 350 pictures – and it's important that you bear in mind that "send or receive", because that £20 buys you a "data allowance", in effect. Got that? Then you take the picture, pick a contact from your address book, pray that they're on the T-Mobile network and have a compatible phone, and send it.

With Orange, all you'll need is a compatible phone. Sending the picture then costs you 40p. And hope your recipient is on the Orange network.

In either of these scenarios, if the person you're sending to isn't on the same network as you, or doesn't have a picture-enabled phone, then they'll get an SMS with a web address (on the T-Mobile or Orange sites, respectively) and a password to view that picture. Alternatively, you could just e-mail it to a standard internet address. (Though don't set huge store by this: a picture I sent took more than a day to arrive.)

As you'll have guessed, I'm not impressed by T-Mobile's charging model. It might make sense to its billing computers, which can easily monitor how much data people have sent over any time period, but humans don't habitually tot up data chunks, and won't feel they're getting value for money unless they send lots of photos – which few people will. It also works out more expensive than Orange, as £20 would buy you 500 sends and unlimited receives.

The other three networks – mm02, Vodafone and Virgin – roughly agree with me on this. Mm02 plans to launch its MMS service in October/November, "in time for Christmas", charging 30p per message – though in a neat piece of fence-sitting, it will also offer MMS "bundles".

Vodafone is "expecting to launch by the end of the year" and its users have told it firmly that they want pay-per-message, not bundling. Virgin, finally, won't commit itself to timings; first it wants to see interoperability between networks (that is, being able to send MMS between any network that offers it) before it jumps in. Orange, T-Mobile and mm02 all say interoperability should arrive by the end of the year; the delay is because it's a lot harder to format pictures and audio for different networks and handsets than it is text.

So if you're in the happy position of being able to choose networks (perhaps you're a student looking to splurge that A-level reward), mm02 looks like the one – as long as you don't need MMS now. Otherwise, it would be Orange. Note that all will require you to be a monthly contract, rather than pay-as-you-go, customer.

To begin with, you're not going to have much choice on the handsets. It's either the Sony Ericsson T68i, which costs £150 and then requires a clip-on camera costing £50, or the Nokia 7650, which costs around £250 but has a built-in camera on the back. They'll send and receive MMS on any of the networks that support it.

Choices, choices. This is a difficult one. Both have Bluetooth connectivity, which I think will become indispensable, especially for synchronising all your contacts and calendar with PCs. Because it doesn't require a particular cable (it's a wireless system) Bluetooth is the ideal way to get these two different beasts to talk to each other. You don't have Bluetooth on your PC? You will. They both need software for the computer too, but that's coming in time.

The T68i is a sleek silver fashion shape, tiny enough to slip into the slimmest pocket. The Nokia is sturdier, a more businesslike machine, whose keypad slides out, revealing the camera on the back. It's so simple a four-year-old could use it; mine did. The real difference is in the screen and camera quality. The T68i loses out there: pictures look grainy, and the camera only captures pictures up to 60Kb. By contrast, the Nokia's screen is larger, sharper, and it takes pictures of up to 100Kb.

There's not much to choose between in the functions available on the phones, so that it truly boils down to style, cost, and quality. If you've got the money it has to be the Nokia – but if you can survive without a camera for now, then the T68i has it hands-down for style.

Beyond that, it's between you and your bank manager. Choose wisely, for you're not going to throw either of these phones away in a hurry.