A grand experiment is underway in London, giving 500 residents a chance to leave their real wallets at home. Instead they’ll use digital wallets on specially equipped mobile phones. Using Near Field Communications, those taking part will be able to pay for travel and also make purchases under $20 sing Nokia phones and contactless payment terminals in a number of shops and restaurants around the British capital. The trial will run until next May. By holding the phone against special posters, they’ll also be able to access maps and information. The phones come loaded with $400 in credit, and users have a helpline to call in case the phones are lost or stolen. Mobile operator O2, which is running the phone side of the trial, feels it’s a service whose time has come. "Research shows more people are likely to go back home and get their phone if they leave it behind, rather than return for their wallet," Cath Keers, O2’s customer director, told the BBC. If the mobile wallet proves to be a success, a full service could follow in late 2008.