Siri, the 'digital assistant', that Apple bundles with the iPhone 4S, has been hacked to work on earlier Apple devices including the iPhone 4 and iPod Touch.
iPhone hacker Steven Troughton-Smith demonstrated the ported Siri in a video, adding that Siri was completely functional on the iPhone 4 despite the single core processor. The port to the iPod is said to function but the iPod's poor microphone hampers the usefulness.
Sadly the hack itself is quick involved and requires a jailbroken iPhone 4S and files which the hackers aren't free to distribute so they wouldn't say when or if it would be made available.
Sadly Siri's iPhone 4S availability seems to be a case of deliberate crippleware on Apple's behalf in order to shift more of the shiny new iPhones.
Perhaps when they're fixing the battery problem in iOS5 they might come to their senses and release Siri on all hardware that's capable of running it. We can only hope.