uVOIPit

uVOIPit is a phone calling service that allows you to make cheap calls to a variety of countries around the world from your PC, mobile or landline phone. You just need to register for free to the service and then either download a softphone application for your PC, an app like Fring for your mobile or make a standard call using uVOIPit dedicated international access codes. No voicemail, SMS service or mobile application are available, nor you can receive calls.

uVOIPit call rates

http://www.uvoipit.com/