A new twist of development has taken place in porting Siri to other Apple devices. A new exploit found would allow users that already own a iPhone 4S to enjoy the exploits of Siri on other iDevices. Sure a unique identifier could be formed but Apple would easily find it and ban it for abuse.
The best thing here is that this may actually hold possibility for Siri to be ported over to Android and other platforms. But the situation will always remain same. You will need an identified for the software to work with Apple’s servers.
So, its time to really see if the friend with an iPhone 4S is actually a true friend.