Generate a certificate authority
Add it to your iPhone
Sign a certificate for "guzzoni.apple.com" using that authority. This should produce the ".crt" and ".key" files your server will need.
Setup a fake DNS server that resolves "guzzoni.apple.com" to your own machine, and configure your iPhone to use it.
Start the "siriServer.rb" server. You will need some ruby gem installed. I have tested it only on Mac OS X 10.7.2 with Ruby 1.9.2.
Make Siri dictation request, for example from the Notes.app application. On the server, this will dump all the "interesting" bits (X-Ace-Host identifier, sessionData and such).
Use them to replace instances of "COMMENTED_OUT" in the code