Not my work

Just ive added some useful links

How to get the necessary bits
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
How to do speech-to-text using a non-iPhone4S machine
Record your voice into whatever format you like
Use ffmpeg to convert the sound to raw sound samples (see the text file for the exact command line). Name it "tentative.raw"
Install the speex library and its header. On Mac OS X, "brew install speex" once you've setup Homebrew
Compile the speexEnc.m file (gcc speexEnc.m -lspeex -framework Foundation -o speexEnc)
Run ./speexEnc. It will produce a input.sif file with speex packets the Ruby script will be able to read
Run the "Siri.old.inline.rb" script. Et voilą !
----------------------//////////////-------------//////------
My Text

How to create your own CA certificate:
http://sandbox.rulemaker.net/ngps/m2/howto.ca.htmlJust put the CA on a webserver then visit on your iOS device :=P
Fake DNS Server
1: Python Fake DNS Server
http://code.activestate.com/recipes/491264-mini-fake-dns-server/2: ApateDNS - Windows
http://www.mandiant.com/products/free_software/mandiant_apatedns/The Siri Files:
https://github.com/applidium/Cracking-Siri