O2 Wallet: Oyster card, Barclaycard and phone in one

Strangely, while the triallists can use the phone for a variety of services, they can't use the installed cash system to top up their Oyster cards to pay for travel -- instead, they have to top it up using the traditional method at busy TfL machines, which still means carrying cash or a card around.

In the final version it would be good to see a cross-platform solution that allowed users to wirelessly top up their credit without having to queue up for ages.