The Transport for London network - which includes Bus, Tube, Docklands Light Railway, Tram and London Overground rail services - is upgrading its card readers this year to allow travel and payment using a contactless bank card. Travellers currently need to buy tickets or use a pre-paid 'Oyster' card.
Although the news doesn't specifically involve mobile payments, it's expected that any NFC mobile payment service would also be compatible.