You must have gone through the news about Applidium cracking down Siri's security protocol so that it can run on any non-iPhone 4S device, even non-apple ones. The hack also gives the developers freedom to develop their own apps and include Siri inside it.
Plamoni is the twitter name of the hacker , who released the source code of the Siri Proxy along with the steps to set it up on the popular social coding website GitHub.
Also he demonstrated that the plugin he created with custom handles allows him to control his thermostat from his iPhone. Commands include "What's the status of the thermostat" or even "What's the inside temperature?" are included in the video.
The creator assures that it doesn't require a jailbreak. His iPhone 4S isn't jailbroken. The only action he says is needed is to instal a fake Root CA. Which doesn't require a jailbreak. Nothing is required such as jailbreaking or coding on the phone itself. He also mentioned that this wouldn't give you Siri on other devices , it only allows to add your own functions to Siri.