EvaPhone provides free internet phone calls. This is achieved by using VoIP   (Voice-over-Internet protocol )call solutions – that is, a service that allows users to use regular telephone networks anywhere through any internet service provider, and avoids issues on long distance charges that are normally subject to callers.
In their own words:
“EvaPhone provides Internet telephone calls for free. Our site offers free VoIP call solutions: free VoIP service lets you make PC-to-phone free international calls. All you need is a computer to start making free VoIP calls using Internet to phone. Start enjoying the benefits of Internet telephony right now!”

Source link: http://www.evaphone.com/locale/en