Developers have ported Apple's virtual assistant to other iPhone versions namely the iPhone 4 and iPhone 3GS and even on the iPod touch.

Apple's Siri has been one of the most popular feature on the iPhone 4S and efforts to spread the Siri love to other iPhone versions quickly began. Developer Steve Troughton-Smith was the first to port Siri to the iPhone 4. He has also able to get server support for the iPhone 4 hack by using some validation tokens from the iPhone 4s.

"It does require files from an iPhone 4S which aren't ours to distribute, and it also requires a validation token from the iPhone 4S that has to be pulled live from a jailbroken iPhone 4S, and it's about a 20-step process right now" Troughton-Smith told 9 to 5 Mac. The developer isn't planning to release the hack as it's more of a proof of concept to demonstrate that Siri could run on the iPhone 4's single processor.

Another developer, Ryan Petrich has also successfully ported Siri to the older iPhone 3GS. The port doesn't work as well as the iPhone 4 port and Siri only works without any ambient noise around. The problem, according to Petrich, is the quality of the microphone that could disrupt the voice app.

Meanwhile, another video has demonstrated a working copy of the Siri on the iPod Touch with the same hardware limitations demonstrated in the iPhone 3GS port. It seems that Apple's decision to limit Siri to the iPhone 4s could be a question of hardware as well as product positioning. To get Siri to work, the microphone has to pick up the user's voice from the ambient background.

A report from Jailbreaknation is saying that Apple is considering releasing Siri to all iPhone 4 owners. A source in the company says that Apple is testing Siri on other devices other than the iPhone 4S. Although this rumor could be good news for iPhone 4 owners it doesn't make much sense for Apple to give away the Siri on other devices. Siri is one of the most distinctive features of the iPhone 4S, why would Apple eliminate that edge? If anything Apple should be testing ways to port Siri to the iPad 2 or to the rumored iPad 2 upgrade or even the iPad 3. Siri on the iPad would be a more feasible step for Apple to take.

Apple's voice controlled Siri was released as a unique feature of the iPhone 4s. The virtual assistant can make texts, appointments and calls for the user through voice activation. More importantly the Siri has its own personality that has managed to charm users with its humorous answers to user queries. Apple is already planning to add more language support to Siri as well as additional features and localizations for the Maps app.