With the iPhone SDK 3.0, Apple introduced new pasteboard functionalities in the core OS. It is possible to take advantage of the pasteboard for sharing audio data between applications.

The iPhoneOS UIPasteboard API can be used to provide users with a flexible audio copy/paste functionality using the standard iPhoneOS clipboard.

Intua’s Audio Sharing Developer Group provides a free open standard intended to expose this methodology to any developer willing to share audio data between iPhoneOS applications. The methodology fully complies with Apple SDK 3.0+ standards and agreements.

Furthermore, the latest Sonoma Wire Works MAPI AudioCopy / AudioPaste protocol is also compatible with this standard.
 

Resources:

Join the Intua Audio Sharing Developer Group and contribute to the project here.

You can download the latest project source code here.

Download the guide for Sharing audio data between iPhone applications.