* Richard Wray guardian.co.uk,

Richard Wray guardian.co.uk,
Philip Makinson, at industry experts Greenwich Consulting, said mobile wallets had fallen down in the past because of the number of people needed to make any system viable.
"It requires cooperation, not just between handset manufacturers and network operators but third parties such as Visa or Mastercard and banks and retailers. To reach critical mass you really need to have at least three of the big operators to be involved or there is not enough in it for the likes of Transport for London or Nokia," said Makinson.
Several of the UK's five mobile phone networks are understood to be interested in mobile wallets.
"There does seem to be consumer demand for it, people are saying they want to carry less stuff around with them," said Makinson.
The results of the O2 trial show that people like using a mobile phone to do more than send texts and talk.
Nine out of 10 of O2's testers were happy using NFC technology, with convenience, ease of use and the status of having such an innovative device cited as benefits of the service.
Top of the testers' wish list was using their mobile phone as an Oyster card, with 89% saying they would use it. The trial showed that having Oyster on a mobile phone led users to make more journeys on public transport.
More than one in five who used pay-as-you-go Oyster on their mobile phone reported that they made more journeys on public transport during the trial. More than two-thirds of users said they found it more convenient to use their phone than a standard Oyster card.
More than two-thirds of testers also said they would be interested in having the Barclaycard Visa payWave feature on their mobile.
Crucially for Nokia, the world's largest handset maker and one of the companies involved in the trial, 87% of the testers said the ability to use Oyster on a mobile phone was likely to influence their choice of phone