Hardware + SAFE data

Prompted by this story of ID cards: Becoming a virtual Estonian
I wondered one powerful application class might be hardware that can access SAFE data, such as a person data set. Some credit card sizes access that would allow a reader to access certain details, as in that article [his doctor, his driving licence, his family circumstances]; passports; voting; etc etc. Such technology to date, suggesting it can hold all your cards in one etc, have never persuaded me but a SAFE access card, might be rather a good option. That could even go beyond what the person/user can edit themselves to be a shared dataset or even a sum of many details.