A developer has managed to get Siri working on the 1st generation iPhone 4 and the iPod touch.
Apple adamantly said that Siri would be incompatible with older iOS devices due to the devices not having "suitable hardware". Well Steven Troughton-Smith has proved Apple wrong and probably made the company look a bit silly.
You may remember a post earlier this month with Siri being ported over but not connecting to the Apple servers to use the data. This was because the device was not authorised by the servers so it would block access to anything but an iPhone 4S. Since the iPhone 4S being jailbroken in the last week, Steven was able to extract the files needed to get authentication from the Apple servers. With these files, he used them on other iOS devices and was successfully able to connect to the servers.
Unfortunately Steven has said would not be releasing it to the public due to it being illegal, and has only carried it out for demonstration purposes. However someone else will most likely do the same thing and submit it to Cydia anonymously for anyone to use.