Sarah is traveling overseas and wants an international cell phone plan. Leo says that it depends on where she is going and for how long. A smartphone is very valuable for traveling overseas. Sarah will be in the Middle East, Israel, Syria, as well as some countries in Europe. She should check out prepaidwithData.wikia.com. She can unlock her phone and get a local SIM that will work in each country. The downside is, she'll have a different phone number. Sarah also uses Verizon, and Leo says that is one of the least capable internationally, but the good news is that Verizon phones come unlocked by law. Since Sarah has an iPhone, then her phone is a world phone and she can put a T-Mobile SIM card in it and get free 2G/EDGE data overseas. She should turn off international data roaming, though.
Lastly, there's the MiFi device. It's a Wi-Fi device that uses International LTE/4G as it's cellular connection, and she can join it via Wi-Fi. Leo recommends the SkyRoam Solis. Sarah can also connect up to five devices, so she can share the rental fee with her friends. She can look for them at the airport.