You can make free calls from Skype to Skype using iphone
the new Call Global app is free to download and the rates are cheaper than skype in most cases and uses the 3g network instead of wifi !
you can find the app in the itunes store or at callglobalapp dot com
Why is Skype/Fring not yet releasing their App to work over 3G?
Now that I can tether my iPhone to Mac, who can prevent me from making a VOIP call using my Mac?
Yes.Is Apple still rejecting VOIP over 3G apps?
VoIP App "Line2" now approved by Apple...after a 3 month wait.
..........Note that most IP applications, like VoIP, are connection agnostic. They do not know or care whether they are connected (at layer 2) via 3G or WiFi. AT&T cannot tell. That is why VoIP will work over 3G on jail broken iPhones. Only Apple can tell that an application is both VoIP and connection agnostic. These are the ones that Apple rejects. Apple's only interest in doing this is to accommodate AT&T............?