Direct TV uses smart cards for renewable security in their satellite receivers. PCS phones in the US will use smart cards. The University of Michigan recently issued 13,000 smart cards and plans adding 100,000 more by 1997. Subways and airport parking facilities in San Francisco, Washington DC and New York are using them. The State of Oregon will use Smart Cards for Food Stamps.
Local banks are probably next.
Some information can only be added and not erased. Stand alone telephone cards will tick off internal registers until pre-paid time is used up. Telephone cards can be self-contained and disposable. They can also be small removable sim chips or reprogramable cards. Portland's Voicestream PCS phones use cards that activate an account, store your PIN number and remember incoming and outgoing phone numbers.