The Times blog has a post about a new cellphone/credit card system--the phone has a chip that communicates to a credit card reader. I believe recently I've also read of a cellphone/ID system, with user ids and passwords securely stored in the phone. So soon all of one's identity can be stored securely in one small device.
The only thing lacking will be a mental link--i.e. for us geezers who have senior moments, we need a device smart enough to sense when we're panicking about being unable to find it.