We already have identifiers on the Internet - email addresses - so why we would choose to carry over cryptic strings of digits from an antiquated system and use those for one communication medium - while continuing to use email addresses as the identifiers for others - escapes me.
I'm still amazed at the number of (mostly small) businesses that I deal with that have ISP domain names in their email addresses. Which seems antiquated to me!
What geeks like us often fail to realise is that for many people - especially small businesses - email is just a tool, it may not be central to their business (ala they may not conduct a lot of business on it, but need the means regardless) and resultantly, it's not their primary concern. Memorable phone numbers, on the other hand, make them readily available to everyone within reach of a telephone, which is still more people than have ready access to email. And by that I mean _right now_, not when they get home to their computers. Enum could be fairly useful as a bridging technology, if nothing else, IMHO. And people who don't have the need for their own domain name, that don't use an ISP based address (the future of which is determined by their ISPs success or failure, and is non portable as previously observed) are using a free email address (the future of which is determined by their free mail providers success or failure, and whilst portable, is 'free' and generally has service levels to match)... tying your long term accessibility to an email address which isnt 'yours' may be as fraught with difficulty as a phone number. (And at least with number portability, you can move your number around; much like you could a personal domain name.) Mark. PS: Happy New Year in Zulu Terms. May all your network devices remain accurate, despite the leap second.