The Sunday Times had a piece about RFID tags today, the usual applications were discussed; supermarkets tracking product lines, tailored advertising etc. What I didn't realise was that I was carrying one in my wallet, the new London Transport Oyster cards contain a Philips MIFARE chip. This was the chip recommended when we looked at these cards to give to students in my last job. The MIFARE system uses one of the Industrial Scientific Medical licence free frequencies at 13.56 MHz, so it is not illegal for other people to have or to use their own reader equipment.
I bought an oyster card last time I was in London, tonight I tried to add more credit online and it said my card was not registered. I need to complete a form at an underground station to register the card, London Transport then have a name and address assigned to my card and my movements around the London Transport system can be tracked, unless I foil wrap my wallet ;-)
http://www.rfidbuzz.com/news/2004/rfid_in_the_london_transport_oyster_cards.html