In a first for US mobile carriers, Sprint has opened up an initial set of REST services for developers to play with for free at their new developer sandbox. With these services (Sprint API profile), developers can now access location, simple presence, and send SMS messages to Sprint handsets without requiring any software installed to the device.
Sure, we live in networked times, but the phone still plays a big role. In about a dozen digits, you can reach anyone in the world with a phone. Now there's also a way to get at much of the metadata that goes along with it, such as where a phone number is likely based. That and more is being made available for free via the Cloudvox Digits API (our Cloudvox API profile).