phone verification: verify user's phone number

Thanks for making this great module! Any chance you plan to add "phone verification" type of process to this module? I am referring to sites like flippa.com, sitepoint.com, google local, and paypal. Basically, the new user is asked to verify their phone number. User puts in phone number, asterisk app calls user and gives 4 digit code, user puts 4 digit code into form field and then submits form.

I see some good uses for this...
- prevent spam, must "phone verify" at least once on said site, before submitting comments nodes etc
- used in the checkout process for ecommerce and ubercart modules, to prevent fraud.

I am willing to help out in this feature request, but I am not familiar with Asterisk. I can help with the Drupal side of things though.