Another benefit of the two-ender technique is its support for multitrack productions. Here, my interviewee recorded his voice and his guitar to separate tracks. I then imported those tracks and my side of the conversation into Ableton Live and synced them up. Track 2 contains the telephone audio, which I recorded as a backup and sync reference; it will be muted.
Incorporating long-distance interviews is a great way to add spice to your Podcasts, but telephone audio quality is horrendous. Here's an old radio trick you can use to get broadcast-quality sound. The technique is called a two-ender because each person speaks into his or her own phone as well as into a separate, high-quality mic and recorder. Afterward, the producer simply imports the two high-quality audio files into two adjacent tracks in a DAW and lines them up (precise sync usually isn't necessary). The resulting mix sounds as though the two speakers were in the same studio.
Of course, this technique requires the person at the other end to be audio savvy. But I heard a variant recently on NPR's This American Life, in which the interviewer sent an assistant to the scene with a digital recorder, and then directed the interview over the phone. You can hear this two-ender interview at http://tinyurl.com/2awtq7. (For more about David Battino's work, visit www.batmosphere.com.)