It looks like Barclays Pingit has some competition, in the shape of the O2 Wallet.O2-branded, but available to all mobile users who use iOS, Android and BlackBerry OS 6 (and above), this is another way of using your mobile phone to pay for goods and transfer cash. You can 'digitise' your credit and debit cards, which in turn allows you to transfer up to £500 via text message. That transfer is free initially, but there will be a 15p charge further down the line. On top of that, you can use your phone for shopping too. With that in mind, there are deals, price comparisons and a number of big-name retailers who will take O2 Wallet payments. Those include Debenhams, Comet, Sainsbury's Direct and Tesco Direct at launch. On top of that, O2 is also in discussions with a rail operator to offer an instant buy button for train tickets and in time, NFC payments will also be added.O2 is certainly confident the service will be a hit. O2 Money MD James Le Brocq said: 'O2 Wallet delivers the benefits of mobile money to more UK consumers than any other product or service currently available. With O2 Wallet, it’s easier to transfer money, track expenditure and pay swiftly and securely, all using your mobile. We believe it will transform the way people manage their finances and spend money.'As for any security concerns, Le Brocq continues: 'We recognise that security is absolutely key. O2 Wallet has been trialled internally for months and has undergone extensive ‘stress-testing’ with security experts. In addition to PINs and passwords, all personal details and financial data are held on remote central servers rather than on the mobile device itself. This, we believe, is the safest and most secure way to deliver mobile payment services.'Just head to your respective app store if you want to try it out for yourself.