I read the FAQ, searched for phone and didn't see anything. I hope this hasn't been answered. That being said:
I have a Samsung Galaxy S5. Will this work or should I pick up a Nexus 5? I ask this because I've heard of something called GSM and am vaguely certain that I need a phone with it and I'm vaguely certain the S5 doesn't have it.
Can I buy a SIM card that will have service over "there"? I'm visiting Milan and Paris for sure but will be traveling around without a plan for a while. Is there a good primer for getting phone service wherever?