I'm coming from Canada (Fido) to NYC for a trip. I have zero plans of using any voice/texts/data while I am on the trip. The only thing I am bringing the phone for, is Wifi while at the hotel and the 5MP camera. How can I disable my carriers features (voice/text/data) so i get no surprises whatsoever in my bill. None of this roaming crap or $5 million bills. Will enabling the Airplane Mode let me use wifi? Is it a foolproof method? Or can I simply leave my sim card at home, and use wifi/camera without a sim card present?