PhoneValidation
===============

I learned a thing or two about North American phone numbers recently.
Check this out, particularly the NPA/NXX format:

http://en.wikipedia.org/wiki/North_American_Numbering_Plan

I think there would be a lot of value in creating a plugin that would
not just check the well-formedness of a phone number, but also check
that the NPA/NXX combination is real. See, not all area codes use all
exchange codes.

My idea for the plugin includes the following:

1. A generator to create the db migration necessary for the new table.
2. A rake task to load in new versions of the db. (it gets updated 4
times a year)
3. A "validates_phone_authenticity_of" function added to
ActiveRecord::Validations.

Bonus points would be to cache the table in memory upon application
load so that you don't need to do a db hit every validation. The data
is nearly static, so refreshing only on app restart is sufficient.

(I'm totally open to other ideas--let me know if you come up with
anything. One idea I have, for v2, is to distinguish cell phone from
normal echanges, and to send an SMS message to validate. Another
obvious next step is to make it work internationally; that's where the
open source community should help.)

This plugin is going to be super popular wherever phone numbers are used.