Why do I still see five signal bars on my iPhone 4S after I've turned roaming and cellular data off? (I am travelling and want to avoid roaming charges). I've followed the instructions found here, and on About.com, and on youtube videos. No luck. Everything is OFF but the 5 signal bars won't go away.
Don't rely on that setting if you want to be 100% sure you won't face any nasty surprises. Put your phone in Airplane Mode...this turns off all iPhone radios. However, you can go back into settings & turn both WiFi & Bluetooth back on.