Sarah is traveling to Vietnam and Cambodia later in the year and doens't know what to bring with her for her technology. Leo says that most electronics are now rated for 110w-240w, so they can handle any circuit all over the world. But that plugs will be different. There are travel adapters for sale that you can pick up to plug in your power plugs. They should be the same as China, but you may want to be sure it's not a french adapter since Vietnam was once a French colony. As for your data and international roaming, it depends on your carrier.