Make free international calls via internet

You can now make international calls via Internet to many places around the world for FREE , or at least really cheap . You can now make calls from your internet to some one's mobile or phone .Well you can make calls from computer to computer for free on IM but how to phones ?Thanks to software's like Voip (voice over ip) and skype this is made possible.VOIP BUSTER:This is a software where you