Took a taxi, bill was about £9 (for a couple of miles in central London, usual rip-off), could have just paid £10 cash, but decided to try the contactless credit card, 10% charge, ok, but then the machines demand a tip as well, and it's not choose your own, but instead they have a choice of %ages, and the options were something like 15%, 20% or 25%. Who are they kidding?