There were some interesting discussions on the VoIPSec mailing list. It started off with Tom Porter announcing his new book, "Practical VoIP Security" and asking for feedback. Well he got some, and it wasn't particularly good, but as Tom pointed out, came from folks who may not be totally impartial.
There was a discussion about how much security affects QoS. Interesting stuff. There is conference coming up focused on that topic: http://www.secqos.org/
One individual asked whether or not there are any public domain tools for SIP session tear down. I did not find any, so I wrote one myself. As I have pointed out before, this is a tricky operation, because you have to know the Call-ID, FromTag, and ToTag. You may need other parameters as well, especially if you are sending the BYE to the SIP phone directly. And of course this gets tougher if the SIP phone requires authentication, uses TCP/IP, or TLS.