Prophecy 2006

Disposable Phone Numbers™ is an open-source project that guards your privacy. DPN allows you to create and distribute unique phone numbers, which you can then control — activate, deactivate, or route in funny ways (direct to voicemail, for example, or even a "fake" voicemail. You can also use DPN to track who calls what disposable number.

This project is available as open source.

Documentation:

• Article in O'Reilly blog
• Soureforge home page (for file releases, some brief docs, and current snapshots)

And no doubt this will crop up elsewhere.

Oh, and to how it works? In the absence of "real" disposable phone numbers, which will be easy enough to do when all phone numbers follow the "sip:foo@example.com" format, the current DPN uses disposable extension numbers.