London would become the first city where mobile handsets would double up as train tickets and credit or debit cards. This convergence is expected to take place by early next year as mobile operator O2 UK has launched trials for its O2 Wallet application.

Around 500 O2 customers will participate in a six-month trial of the technology across a number of sites throughout London.

Along with partners including Transport for London, TranSys, Barclaycard, Visa Europe, Nokia and AEG, trialists will be able to use their mobile phone for services such as travel on the London Underground, credit card payments, Location Based Services delivered via smart posters, and electron tickets for entertainment.

Each trialist will be equipped with a Nokia 6131 NFC (Near Field Communications) handset installed with the O2 Wallet and can use the services simply by touching the card to a reader.

Cath Keers, customer director of O2 UK said: “This trial is going to provide insights which will prove crucial to getting the customer experience right as we bring NFC on mobile to market. But the trial is just the start of this journey. For this to work we will need the whole ecosystem to come together which means mobile operators, banks and retailers all working together to fulfil a shared vision.”

Observers expect such devices could come into commercial usage by the end of 2008 at the earliest. Richard Humbach, head of the NFC Business Line for Nokia''s Emerging Business Unit, said he expects NFC to be a mass market technology within the next two to three years.

However, building a critical mass of devices will be key to the technology's success and Nokia could not put a date on when NFC technology could be implemented into the SIM card. "Over time the technology will move to the SIM," said Humbach. "But the standards are not complete and the technology needs to progress, so at present it's tied to the handset," he said.

However, security firm Gemalto and NXP Semiconductors are known to be collaborating on a SIM-enabled NFC platform which will work with NXP's MIFARE technology. MIFARE is used as the Oyster branded contactless ticket system on London's public transport network and could potentially see the technology used in any device, simply by changing the SIM card.