Siri is supposed to be automatically engaged when you raise the phone to your ear. Apparently, there is a motion sensor in the phone that detects the movement of raising the phone to your ear. Unfortunately, I have had just intermittant success with this as Siri sometimes does not come on. I am forced to manually push the home button in order to activate Siri. Anyone else have this issue? Could this be resolved by re-booting the phone? Thank you.