For past few months, many hackers and developers have been trying to port Siri into older Apple devices.
Most of the features of Siri worked in iPhone 4 and some also worked in iPhone 3GS after a little jailbreaking. So far it has been seen that as a technology, Siri does not require the A5 processor of iPhone 4S.
Now there is a new development in this regard. A developer called Eric Day has recently uploaded a new jailbreak package called Siri0us which he has described as “having Siri dictation for iOS5 devices.” However, to port Siri in older devices, the iPhone 4S keys and files were required. Now thanks to a new jailbreak tweak, this is not the case anymore. This tool is accurate and runs smoothly. It has been tested on many devices and so far has been working fine. Dictation is largely accurate. The technology is Nuance based dictation. However, in the end, it is quiet similar to Siri.
Siri0us has worked for many and though, it is not make Siri fully functional the way Siri is in iPhone 4S, it does provide some utility.