Over the last couple months I have become a big Skype user. Not the free version, but the paid “call any landline in the world” version. I use it on my iPhone via Wi-Fi in hotel rooms and on my laptop when traveling.
The world of voice calls was very unaffordable for the traveler only a few years ago. I cannot imagine being without it now. $13 a month is a small price to pay to be able to call home wherever I am for as long as I want.