Having an unlocked phone enables you to buy a sim card in each country and have a local number and local phone service.
In Panama City, I met the bright, personable, and trustworthy Karol. Karol was headed up to Costa Rica so I gave her my CR SIM card.
Service with CR’s ICE is so inexpensive that I had plenty of service left on the card and it might come in handy for her. I insisted she take it. A few weeks later she returned — with stories of how that sim helped make her trip a great one.
This is Karol’s short version of her story, which she called a butterfly effect.
Update 2018:
Well, that was her story. Her blog is gone and I can’t find her.
Lesson learned.
When you link to a post or article, also keep a copy of the words. It was a beautiful story about how my SIM card enabled her to meet up with a CouchSurfer who took her to fabulous places, then introduced her to someone else. And how because she had the card, she was able to find and meet others. She would not have had those experiences if she hadn’t had cell phone service.