Can I change the default camera app on my iPhone? In the latest iOS update (5.1) Apple added the camera to the lock screen, so now I don't need to unlock the phone to take a picture.

Is it possible to change which app is used for this?

I realise that there are potentially privacy concerns around this which the default app nicely resolves by only showing those photos taken in the current session in the camera roll, but regardless, is this possible?
There is no native way to do that.