Nice idea! Would it be crazy to just use an email address as the pointer? It's easier to remember than a random string of numbers and it means they don't have to worry about name spacing. They can initially verify it by emailing you, like everything else.

And who would curate the mapping? A government department? USPS/Royal Mail? And is it public information, or should some 'privacy' laws apply? If it's the latter, how is sharing that with e.g. FedEx going to be regulated? We don't want to recreate the zip/post code mess!