Great. All you need now is unbreakable security like Microsoft DRM.No .. wait .. that's been broken twice already.Um .. Apple Fairplay.No broken already.Hmm ... tricky.

The problem is that if you have one card to rule them all and it gets cracked, then you are royally screwed. You may as well send all your personal info to the phishers right now.

Always devise confidential information systems in such a way that when the security is broken, you lose control of the least information, not the most.

I worked as an engineer in the port industry for a while and we tracked people strictly by their fingerprints. We'd do all two-finger pairs, so if they got cuts or something, they could still get their privelages. No cards were necessary at all. We could scan a person and have their fingerprints matched from a group of 20K in about three seconds.

The user never has the to carry their own data with them this way, the data has to be stored by the people that need it. This way, your bank won't have access to data about your health insurance, employment privelages, etc.

This worked so well for us, I really think carrying around any cards at all will be over in ten years.