I'm starting to plan a trip of 1-2 months from the US to Europe for next year,camping and staying in hostels.Anyone have advice as to my iPhone? I already know to turn international data roaming OFF.Is it possible to buy a SIM card over there to just use for the trip?If so would that be a good idea? I'm thinking I'll visit the UK,Germany,Czech Republic,Austria,Switzerland,Ireland,maybe Poland. Thanks!!