Part 1 of 2 articles: the second covers cellular data in Europe Last updated: October 2017 To many Americans, staying in touch with a cell phone or tablet while in Europe can seem difficult and expensive. But savvy travelers know it doesn't have to be. Having a phone while you're there can be a major time saver and convenience. This article tells you how to stay in touch and save money. Why don't US cell phones "just work" in Europe? For various reasons, the United States developed and deployed wireless technologies that were incompatible with those deployed in the Rest Of the World, which went with a standard called GSM ("Global System for Mobiles" - one of the reasons why Europeans use the term "mobile" and not "cell phone"). This meant that for many years, the only option for US travelers to Europe was to rent a GSM phone, which was expensive and inconvenient. But all that has changed in the past few years.