Is an iPhone really off when it's off?
I have a relatively new iPhone 3GS which appears not always to be off after it has been switched off.
During the past two months there have been a number of occasions when I have switched the phone off before a flight - I depress the OFF button, slide the Power Off slide, watch the whirly wheel spin and fade and then press the HOME button to confirm that the phone is indeed dead.
On some occasions, on switching the phone on again after arrival, I have found it to already be on (no boot-up cycle); on two occasions I have received a text message whilst taxiing within minutes of switch-off and on one occasion I received a text message at cruise altitude somewhere well north of Moscow.
I have not managed to replicate this outside an aircraft environment.
Has anyone any similar experience or rational explanation for this behaviour?