Skype calling
Our daughter lives in Spain and we use Skype consistently to talk with her. You download the program for free on to your computer and set up your account with user name and password. You can then use a credit card to purchase Skype credit, usually in $10.00 increments. After that, all you need is an inexpensive headphone/microphone combo.
Calling from computer to computer is 0 cents per minute. Calling from your computer to someone's housephone/land line is 2.7 cents per minute to Europe. Calling from your computer to someone's cellphone costs 27 cents per minute. Reception is clear and reliable. The only down side is that you are attached to your computer because of the headset. We do own a laptop and carry that and a headset when we travel. It is possible to set up a webcam or instant message on the system also. I am not sure what happens when you are out of the country and call into the states. My daughter's Spanish boyfriend has signed on to his own account (set up in Spain) and called his parents in Barcelona from our computer with no problem. We've been using Skype for over two years and have nothing negative to warn you about.
Good luck with your decision.