The London public transport network is among the oldest in the world, but its fare collection system is far from being old school.

When I was there last month, I did not even have to buy an Oyster card - the equivalent of Singapore's ez-link or Nets FlashPay stored-value contactless cards - to travel from place to place. Instead, to travel on the underground rail system, for example, I tapped my iPhone on the fare gates' payment readers.