The most affordable way to stay connected is to rely on Wi-Fi to make calls and get online. If you’re stuck in a hotel, plug a $99 AirPort Express into the wall to turn an Ethernet connection into your own personal Wi-Fi network so you can use your smartphone and other devices.

If you plan to venture out frequently, try Xcom Global’s MiFi rental service, which for $15 a day will give you a palm-sized device that acts as a local hotspot. This enables your smartphone to remain connected at all times—vital for using mapping and online translation services in foreign countries. You’ll also want to sign up for Skype and Google Voice accounts, which let you send messages or engage in free or low-cost voice and video chats with a Wi-Fi connection. Using those services will also help the people you’re calling avoid any possible charges for receiving calls from an international number.

If you’re going to a country where you can’t use Xcom’s service or easily get Wi-Fi in other ways, be prepared to spend to buy an unlocked phone with a SIM slot and GSM support for foreign countries. Go to eBay or Negri Electronics, which sell smartphones that aren’t tied by software to a specific carrier, starting at about $200. It’s expensive, but having an unlocked phone will at least allow you to rent a prepaid SIM card in whichever nation you happen to be in, so you can pay local rates instead of astronomical roaming fees.