A new OV Chipkaart system has been introduced in Amsterdam this year, and it will be available in all of the Netherlands in a few years. The concept is generally OK: no more counting of strips on a strippenkaart or buying train tickets; just transfer some money to the card and go (there is the thing where the card issuer can track who went where, and when, but I trust that will be resolved in time).
But there's a usability problem with the gates: it's not immediately obvious where you