DEAR MS. SMARTPHONE: I’M ABOUT TO EMBARK ON MY FIRST EUROPEAN VACATION AND I’M STRUGGLING WITH THE DECISION WHETHER OR NOT TO BRING MY iPHONE. WHILE I DO WANT TO ENJOY MY VACATION I’M NERVOUS ABOUT FOLKS NOT BEING ABLE TO REACH ME. WHAT SHOULD I DO? AZ, Sausalito Dear AZ: I would not let…