Seen this talked about in a few different threads as a side point, thought it would be good to discuss it here. My thoughts are no. It will be a built in function of iOS5, so the only way to get it would be for someone to hack apple's source code and convert it into an app. If a jailbreaker did that, I think you'd see Apple looking for the excuse it has been wanting to sue the jailbreakers into oblivion. Right now, I think Apple knows it wouldn't have any leg to stand on in trying to sue jailbreakers. If they hacked and stole their source code, hasta la vista jailbreakers. That and I don't even know if you could hack the code that way very easily in any regards, because of how deeply it's integrated into iOS5. Also, it accesses Apple server farms, wouldn't it be pretty easy for Apple to be able to tell that a jailbroken phone is trying to access the siri servers? Even if they don't know your phone is jailbroken, couldn't they easily tell it wasn't an iPhone 4S and thus HAVE to be jailbroken to access the Siri servers? Those are my thoughts, other opinions?