Siri must have a feature exclusive to the iPhone 4S, but will port to many older Apple devices.

Engadget, a technology website, reported that a team of hackers “euwars” and “rud0lf77″ Siri succeeded in port on an iPod Touch.
The team released a video SIRI port for iPod Touch  them on YouTube. Figure shows the screen to enable or disable the Siri to an iPod.

After the release of the iPhone 4S, Siri port rapidly evolving in the iPhone 4.
Developer Steven Troughton-Smith, an association of 9to5Mac, able to upload it to the iPhone 4 SIRI interface .

However, he did not exactly manage to connect to the server Siri Apple, because the company did not verify his command to the server from iPhone 4 or other devices.

Hackers have found the same problem with port Siri it, because it is a developer who has the port Siri the iPad, and iPad 2.
Industry experts suggest that Apple may want Siri to be a program especially for the iPhone 4S as a special microphone, or because the processor A5 in iPhone 4S allows it to run faster.

Apple has not commented on why it would not allow other devices to run the Siri. It simply states the program is “exclusive” iPhone 4S.
9to5Mac, a technology site, previously mentioned there is no technical reason why Siri can not run on the iPhone 4.
iPhone 4 hardware is capable of supporting the Siri artificial intelligence system.
“Processors A4 in  iPhone is to be strong enough to run a program like that,” says 9to5Mac.

Here a video for SIRI on iPod touch