This is an idea from several years go I've never written up fully, but it's one of my favourites.
We've seen lots of pushes for online identity management -- Microsoft Passport, Liberty Alliance and more. But what I want is for the online world to help me manage my physical identity. That's much more valuable.
I propose a service I call "addrescrow" which holds and protects your physical address. It will give that address to any delivery company you specify when they have something to deliver, but has limits on how else it will give away info from you. It can also play a role in billing and online identity.
You would get one or more special ID names you could use in place of your address (and perhaps your name and everything else) when ordering stuff or otherwise giving an address. If my ID was "Brad Ideas" then somebody would be able to send a letter, fedex or UPS to me addressed simply to "Brad Ideas" and it would get to me, wherever I was.