phone

It sort of depends. You can Skype (video & voice) for free laptop to laptop/desktop, you can Skype laptop to phone for $10 for a bunch of time, you can use an international calling card...doesn't matter which one...they're all very cheap, you can use a mobile phone – yours, a rental, a prepaid phone, etc., or you can Facetime Apple to Apple. A few more details about your calling pattern and where you'll be would help.

I used a PIN Card purchased from newstand or convenience store and payphone for years. It's still not a bad choice. If you're packing either a tablet computer, Ipod, or Smartphone, Skype is the way to go. You can set it up to dial land lines for a couple of cents per minute - or call other computers that have Skype for free. Use WiFi (generally pronounced WeeFee in Europe) at most hotels, and many cafes and bars. If all else fails Starbucks and McDonalds have free wifi. I really liked using the Ipod. Not only for calls but as a place to store my documents, hotel phone numbers and addresses, music, travel alarm, weather reports, email, etc.