Cloudvox Digits API

Cloudvox Digits is a free, public, multi-protocol API and Web service for turning a phone number, area code, or prefix into geographic location, carrier, and other metadata. The service can be consumed via browser, REST API, DNS API, and bookmarklet. Digits was built to be used by Web apps, phone services, and other software that displays or interacts with phone numbers. Augmenting phone numbers should be painless, fast, and free.