in some places, vending machines accept contactless smart cards, which makes it much easier to pay - http://en.wikipedia.org/wiki/List_of_smart_cards http://en.

in some places, vending machines accept contactless smart cards, which makes it much easier to pay - http://en.wikipedia.org/wiki/List_of_smart_cards http://en.wikipedia.org/wiki/List_of_smart_cards More easy for countries where it is supported everywhere, rather than regionally. But also possible to target vending machines in transit areas, since a lot of public transport has moved over to smart cards.