hi, I'm going to head overseas for a few weeks and plan to take my iphone. i know on the flight if i need to use it, play games, watch a movie, etc.. (no calls) i can enable airplane mode. but once i land, is there anyway for me to have the phone on, but stop the iphone from trying to connect to the local cellular network. i do not want to use the phone to make or receive calls once overseas, but would like to use it for wifi or ipod features. is there a setting i can enable or disable to do this? airplane mode i believe would stop cellular connection but also wifi, i might want wifi on once i've landed. thanks.