I feel like a technology cripple. I had a trip to Canada last month with a 2 night layover. I don't normally fly out of the US. 20 minutes of phone calls cost me $20.54. Roaming Data cost me $114.38. Total bill $134.92. I had no idea. Lesson learned. After I got my bill I figured out you could turn of Data Roaming. Go to Settings-General-Network-Data Roaming and turn it off. Any other suggestions? My bottom line from now on is I will not use my phone in Canada unless absolutely necessary.