Audio Hijack Pro has been updated to better capture phone conversations [1]. No, the folks at Rogue Amoeba haven't signed up with the NSA. Rather, they've recognized the ongoing interest in recording Voice over Internet Protocol (VoIP) calls, whether computer-to-computer or computer-to-PSTN (Public Switched Telephone Network - you know, the real phone network).
Audio Hijack Pro 2.7 bypasses a fairly wacky setup that I described for O'Reilly Networks [2] last year, and worked with Andy Affleck-Williams to build into his "Take Control of Podcasting on the Mac" ebook [3], which I edited. Audio Hijack Pro is designed to capture sound from any application or system resource and pass it through. Combining multiple capture streams enables live mixing, and built-in filters enable live processing, too.
The difficulty was, primarily, when recording a podcast or for other purposes, having the sound on a headset's earpiece totally or partially suppressed to avoid echo, while still recording each voice. It was also impossible within Audio Hijack Pro to capture each side of a conversion separately without recording separate audio files and mixing them later in another application.
The newest version, a free update for existing registered users, adds MegaMix, which enables hijacking of both sides of a conversion, with an added option to record each voice separately. Simply creating a stream (Session > New) and choosing a VoIP program handles the details. You can modify the default choice of mixing down both sides of a conversation by clicking Advanced in the Input tab and checking Separate Inputs and Outputs by Channel. (Rogue Amoeba has good illustrations in this blog entry [4].)
Solutions already exist for several major VoIP programs. Apple's iChat AV [5] can record directly to GarageBand 3 [6], with one track per participant in conference calls. A new plug-in for Skype [7], Ecamm Network's Call Recorder [8], enables multiple track recording within that software. The Gizmo Project has long provided direct MP3 recording [9], too.
[1]: http://www.rogueamoeba.com/audiohijackpro/
[2]: http://www.macdevcenter.com/pub/a/mac/2005/10/10/how-to-podcast.html
[3]: http://www.takecontrolbooks.com/podcasting-mac.html?14@@!pt=TRK-TB840
[4]: http://www.rogueamoeba.com/utm/posts/Article/ahp27-tour-2006-07-31-12-00
[5]: http://www.apple.com/macosx/features/ichat/
[6]: http://www.apple.com/ilife/garageband/features/ichatrecording.html
[7]: http://www.skype.com/
[8]: http://www.ecamm.com/mac/callrecorder/
[9]: http://www.gizmoproject.com/screen-shots.html