I don't know about RFID, but many credit cards are coming with ISO-7816 smart chips for added security

RFID is a proximity technology. The minute you walked in the door, the store could read your card and start charging you. You'd need to keep the card it a conductive envelope to keep it from being readable all of the time. I think it's not such a good idea unless you trust all of the stores.

I've designed kiosks that read cards for ports--seems our government has a propensity to overdo-things. The newest TWIC (transportation worker's identification credential) has a mag-stripe, a 3D bar-code, a picture of the worker's fingerprint, photo of the worker and an RFID. Originally, they were also going to build-in the European contact-reader--I don't remember if it's there too. Our Kiosk can read any of these.

But when a worker comes into a port, we scan two fingers ultrasonically and match in three seconds. The card--and all of it's technologies--aren't that useful. After the match, a remote person can check the photo of them standing there in front of the kiosk with the file-photo on them, but mostly the system runs automatically.

I guess the TWIC card even works as a debtit card. Seems pretty useless to me. Lots of money spent on a card.

http://en.wikipedia.org/wiki/Transportation_Worker_Identification_Credential

I know that RFID is a proximity technology. The basic idea isto have your credit card swiper (to alert the store authorities) to catch the lurking card thief.

sorry, I didn't understand. I thought you meant to duplicate the magstripe.

If alarms are anything like at the local Walmart here, they go-off on about every sixth customer, so people pretty-much ignore them.