From Ambrosia Software:
WireTap Anywhere provides you with a professional virtual audio patchbay for your Macintosh. Any program on your computer that generates audio can show up as a virtual audio input device, allowing you to record or process it in any other application that works with audio. For instance, you could record both sides of a Skype or iChat conversation directly into Peak for editing... or go the other way, and pipe the audio output of ProTools over Skype or iChat for a friend to listen to. With WireTap Anywhere, your applications are instantly transformed into audio inputs. Record the audio output of any application from within your favorite audio application. Tap your audio -- anytime, anyplace, anywhere.