Tech blog InTech-BB on Sunday reported that a group of iOS hackers successfully ported Siri, Apple's virtual personal assistant, to iPhone 4 and iPod Touch 4G.
Fortunately, we have found a successful port which will give you the complete GUI and the connection with Apple servers, the blog reported.
The blog posted the link and instructions of how to get Siri on the listed iDevices.
From the comments on the InTech-BB post it seems many users have followed the instructions with success. However, some have reported a few snags after installing such as camera problems. However, a fix seems to be available.
The blog indicated that the unauthorized software works only on a jailbroken iPhone. It provides the guide to jailbreak iPhones.
Jailbreaking your iPhone can cause problems with your device, so it is best you exercise caution when you read the how to guide on InTech-BB and decide if you want to add Siri on your iPhone 4 or Ipod Touch.
You can read more here.