[baseonmars]

i'm not convinced... i kind of like the anonymity a telephone number affords.

[throw_away]

Moreover, people who want to change how phone addressing works rarely consider the fact that the people who can email me are not the same people who I want to call me on voice. Or the fact that sometimes I change my number with the intent of denying that ability to people who knew the old number. Or the fact that the region-locality of numbers often yields useful information about the person on the other end.

[SwellJoe]

These are social problems with simple technical solutions. Making it default to going to voicemail, with only a whitelist of callers ringing through, is one possible solution. Having it respond with a message that suggests using email instead is probably the one I would use, since I hate phone calls from just about everybody, except family.

[sharpn]

Agreed. I don't want anyone to be able to guess my cell number & spam call me, why would anyone want that?

[sketerpot]

Then use something like an URL shortener to get as many anonymous phone addresses as you like.