I live in the U.S. and am going to Canada on vacation. I don't want a huge charge on my bill while there, so I won't be using my iPhone to make calls or download data through AT&T. But if I use free Wifi with my iPhone, will I get some huge international charge? Or is it just like here in the states? If I can use a free WiFi connection then I could still make calls on my iPhone via Skype and get my email for free....yes?