Phone and Data Charges - From the 4/27/15 news 4 companies do not charge the 3% foreign transaction fee, Capital One, HSBC, Pentagon Federal Credit Union and Discover. This is related to the embedded chips which make the transaction more secure. Note that all charges will be based on the current exchange rate. In Canada we use the PenFed Cash Rewards card which gives us 5% monthly cash back on fuel purchases including propane and use our Discover card for other purchases.
Data can be very expensive and you may get significant fees regardless of what your carrier tells you beforehand and this may include a prepaid SIM card. While in Canada we add Verizon phone access for $15 per month, turn off data on the phones and use WiFi for the computers. Call Verizon before you enter Canada and after you leave.
In the US we use the PefFed card for fuel purchases and AmEx (5% yearly cash back) at the truck pumps.