If you've used an Oystercard on the London tube, you've used what is called Near Field Communications (NFC). You get the card near the reader rather than having to make physical contact.

Such contactless tickets or passes are common in Europe; key fobs, for example, open office doors across the UK. In Hong Kong you can use the same Octopus card to pay for bus, train and ferry journeys or to buy a cup of coffee or an ice cream when you get off the bus.

And anything that's small enough to build into something the size of a credit card can be built into a device you already own, a device you already carry with you every day - your phone.

In some surveys people claim they'd be more worried about leaving their phone at home than leaving their wallet behind; with NFC, your phone can be your wallet. It can be your train ticket, your library card, your supermarket loyalty card, your gym membership, your cinema ticket, even your credit card. According to Nokia's Gerhard Romen, "touch becomes the new click".

A wireless world

Take it a step further - anything you can touch, you can connect to. As Romen puts it, "touch provides an intuitive interaction between devices".

Microsoft has demonstrated NFC as a way of setting up a wireless connection between a media center PC and a smartphone. Nokia set up a smart bus stop that can tell your phone how long your bus will be. Romen suggests you'll be programming your phone as the key for your hotel room or tapping it on a digital picture frame to tell it to send a photo via Bluetooth.

To do any of that, though, we need NFC in more than just the one phone (the 6131) that Nokia has brought out so far, and we need operators and services to sign up. Analysts are predicting that by 2011 we'll have nearly 500 million NFC enabled phones and be spending $36 billion in contactless payments.

But Transport for London's has already tried and failed to turn Oystercard into more than a ticket service, because of political rather than technical issues. The banks are worried about losing margins, everyone wants someone else to pay for the infrastructure, retailers need convincing that there's money as well as customer convenience involved and mobile operators have to see a good reason to subsidise phones with NFC built in.