VoIP will be on the iPhone SDK but with WiFi
For some time now it has been looming, the question of VoIP on the iPhone that is. Well apparently no more! Steve Jobs said at an SDK launch: “ VoIP will be available on the iPhone if it is not using to use EDGE network.”
Furthermore, iPhone SDK doc states: “If an Application requires or will have access to the carrier network, then additionally such Application: …May not have Voice over Internet Protocol (VoIP) functionality.”
What this means is VoIP applications need to be specifically written for the WiFi network; hopefully it won’t take some developer to come up with a rewritten application, and once that happens VoIP will be on the iPhone!
Source — arstechnica