I am from Canada and I am going to South Asia soon. I want to take my phone (Galaxy 7500). I am going to cancel my phone plan here before I go. So I want the phone for WiFi and camera and data organizer. So if I don't have a calling plan: 1. Will I be able to use WiFi? 2. If I stay somewhere for long enough that I want to make calls, can I use the Sim card in my phone, or do I get a new one? If so, will I lose all my contacts, notes, apps, etc? Or are those on the hard drive? 3. Is WiFi the same all around the world?