As most Apple iPhone users are aware of the new Siri on iPhone 4S which lets users to use their voice to send messages, schedule meetings, place phone calls, and much more. Siri understands what you say, knows what you mean, and even talks back. Siri personal assistant application for iOS is available exclusively for iPhone 4S only.
As per Wikipedia
Siri is a personal assistant application for iOS. The application uses natural language processing to answer questions, make recommendations, and perform actions by delegating requests to an expanding set of web services. The iOS app is the first public product by its makers,who are focused on artificial intelligence applications.
Few days back, one of the iPhone-Dev team members musclenerd tweeted about a possible port of Siri from iPhone 4S using a alow level exploit in A5. But he said, its not possible unless someone use some form of piracy.
Developer Steven Troughton-SmithÂ and 9to5Mac seems to have been able to get some success in porting the iPhone 4S Siri voice command system to the iPhone 4. They were able to install the iPhone 4S Siri onto an iPhone 4. Siriâ€™s interface loads up on iPhone 4 with all the features from the iPhone 4S implementation.
The ported Siri on iPhone 4 was able to recognise voice commands using both the standard Siri view and the keyboard Dictation view and even able to communicate back. Though the ported Siri App at the moment is sluggish and perform slow due the non availability of GPU driver for iPhone 4. Apart from this, there are also some authentication issues too with the Apple servers.
The most important point which this port is emphasising on is that Siri can be run on iPhone 4 technically if Apple wishes to allow that.
This port is still a work in progress and we will wait more progress on this front. Hopefully a fully working port of Siri will be released or may be Apple does something with it.
PS: Siri is available in Beta only on iPhone 4S and requires Internet access. Siri may not be available in all languages or in all areas, and features may vary by area