A System to reduce personal data redundancy

I have a problem. A simple problem. If I am allowed to sit tight in a corner with nothing to do, I start thinking of new ideas. Now the problem is I dont know how to continue working on those ideas.
The idea I got this time is quite a neat one, I mean it, a seriously neat one.


How many times do, you, as a net-aholic type in your personal details. Your name, address, DOB. etc. Of course this time could have been saved to do something more useful (like reading more blogs :-) ). Now imagine you shift to a different place of residence..... Further, you decide to give up your christened name and decide to rename yourself, after being  inspired by that guy/gal you saw in the theatre.  How many sites do you have to update??? How many days do you have to spend????? (Unless of course you still use that old style of shopping, I mean the manual one, which includes walking). The number of days you spend can be considered to be down time(as in the time wasted on a computer while installing maybe an OS).

What if this time could be saved after all.
What i a solution to all this was found. What if a system was designed which does this for you. No, I am not talking about robots which manually change the address at each and every site.
I am talking about a system brought about by a company which stores all the required information in a single central repository. All other systems which require it (meaning banks, shopping sites,etc.), would have to just securely connect to the system, retrieve the data(which it is authorized to have) whenever required.
Imagine the redundancy and associated problems that is reduced. All the user will have to do will be to update this central repository when he changes his name, address etc.
To authorize a site to have certain data all he should do will be:
2 options over here
1.               Login to the central repository, and command the system to give only certain details to the site.
2.               Login to the central repostiory, and generate a key which when passed to the site authorizes it to retrieve certain contents, from the repostiory.
Of course in both cases the Login will have to be done securely.
Sounds good???? Sounds good to me. Guess the world is waiting for me to come up with the company to manage this central repository. But who knows..........................