Gadget Master

His system lets you use Siri as normal, except that all commands pass through a proxy server. Apple's official Siri servers interpret voice commands as usual, but the proxy server intercepts the returning text, making it possible to create plugins that run custom commands. For example, Lamonica hooked up Siri to his wirelessly controlled thermostat, letting him ask for the current temperature or set a new one.

Lamonica says the system should open the way for others to hack Siri, just as the reverse-engineering of Kinect opened the device up to a variety of creative hacks. "We're already seeing a new wave of hacks. I published my code less than 48 hours ago and I've already seen other developers use it to write a Twitter plugin and a plugin that gets hockey scores," he says.

The hack builds on previous efforts from Applidium, a French mobile developer company that last week figured out the protocol behind Siri. It turns out that Siri could theoretically run on any device, not just Apple's latest handset, but the servers will only respond when provided with an unique ID number tied to each individual iPhone 4S.

It may be possible to use an unauthorised device by providing a genuine ID number, but it would also be easy for Apple to block an ID used for requests that seem to come from something other than a 4S.

Lamonica's system currently only works on a 4S, but he says that Apple could still stop it from working by signing each response from the Siri servers then having the Siri client verify this signature. "It would make it impossible to do this kind of "man in the middle" attack where we actually inserted or modified the responses," he says.