Hello from Gregg C Levine They are. They are widely used in Japan, and in some parts of the EU. No I don't know from experience, more like from discussing the issues from people who have been there. I think in S America for the e-cash approach, certainly with Brazil, for the buses, they use i-Buttons from DallasSemi-Maxim. Gregg C Levine drwho8 atsign att dot net