The latest update of iOS (5.0.1) has a minor flaw that will let you port Siri, the best virtual secretary on the planet to iPhone 4. Earlier Siri was locked in iPhone 4S, which resulted in the huge demand even though 4S had only a camera lens upgrade over the 4. But the iOS update allows access to system files which were previously encrypted.
Musclenerd tweeted that this is the first iOS image(the .ipsw file) that contains decrypted ramdisks. We are guessing it might be a mistake by Apple!? He also says that it is legal to port Siri, thanks to Apple’s (un)known mistake. But you still need an iPhone 4S’s UDID to make it work. Moreover it needs to be switched every 24-hours to avoid detection.