Mobile Phones for Overseas Travel: A simple battery powered device, so essential to everyday life. You just expect them to work. When you take it overseas the main issues are your service plan, unexpected roaming charges for calls or data and you'll probably need a new charger or at least a power-adapter, but unexpected problems can come up.
We arrived with two smart phones. We left one attached to our T-mobile account from the states, so we could continue to call state-side numbers without any tolls. T-mobile also has a very generous (unlimited data & texting) while roaming internationally so that means all the apps, maps, navigation, web browsing, etc are still working as normally in England, even if it still costs $0.25/minute to dial a UK number for voice. While we keep universal data connectivity with this phone, the roaming speed does drop to 3G speeds, which can be annoying at times.
For the second phone, we purchased a monthly plan on Three Mobile with unlimited voice, text and generous chunk of monthly of high-speed data. This phone allows us to call and receive from all the numbers in England toll-free as much as we want, which will be important to carry on local business here. While the data connection is full speed, this phone will have expensive tolls to call USA numbers. We set this up in the USA before departure and verified it was working before we set out.
Independent of those mobile accounts, we also set-up a Google Voice account on each phone. The Google Voice accounts allow us to talk, text directly to any US phone numbers from wifi signals or from the mobile data service for free. This effectively bypasses all the phone system infrastructure and sends the voice calls directly over the internet, but unlike Skype, it allows you call any US number directly even land-lines without any charges and assigns you a fixed phone number that can also receive calls from every phone and take messages. All very handy in theory. Once again we set all this up before departure and tested everything out back at home.
In practice, we had some serious issues that took quite a while to sort out. First, Becky's phone had the new Three-UK account and sim-card that had been activated before we left USA. Upon landing it should have just worked. Yet there was no joy. The phone kept reporting a strong signal, but no connection to the network. In addition to no UK voice calling, we didn't have data on that phone either (without wifi). That meant we also couldn't use the Google Voice on that phone while away from wifi signals.