"Last year, I took a trip to Asia. To stay in touch, I carried a GSM world phone, capable of receiving telephone calls in the countries I was visiting. The capability to receive calls with the same mobile phone number I use at home while halfway across the world seemed incredibly cool--at least until the first call came in! Mobile phones hide the location of the phone, which cuts both ways. A colleague had decided to call me in the middle of the day on a Friday, which had awakened me very early on Saturday morning, because the phone 'hid' my faraway location from him.
"After returning home, I asked several people why my phone company could not simply play a message to warn callers when my time zone changes by more than four or five hours, letting them know the call might be inconvenient..."
