Phillip Zimmermann of PGP fame outlines the future for VoIP encryption. A few years ago it began with PGPPhone; now called zPhone. He's provides clarity on how to handle "man in the middle" attacks. His beta will be released at the end of February. This is definitely one to watch.

(Note, this was recorded on my iPod with iTalk, it is not meant to be IT Conversations. In a few weeks I'm sure many of these will be available there)