Previewed at WWDC, launching in the fall.
SDK Changes Open Door to VOIP Over 3G Networks... iPad Phone Calls Possible?
With the latest revisions Apple has made to the iPhone developer agreement and Software Development Kit, iCall for the iPhone and iPod Touch now enabled unrestricted free local and long distance calling over 3G data networks.iCall claims to be one of the few VoIP applications that has been permitted by Apple to operate on the iPhone platform. This allows users to make telephone calls over AT&T's 3G data network without using their plan's minutes.
The no-VOIP-over-3G restriction had been in place since the launch of the iPhone SDK due to Apple agreements with AT&T. AT&T announced that it would allow such applications back in October and Apple promised to make the necessary changes.
The change comes with the launch of the Apple iPad which suggests that these same applications could be used to make voice calls on the new device. The 3G enabled iPad notably does not include any voice service with its $30/month unlimited data plan, but it does include a microphone and speaker. We're not sure if these iPad data plans will be somehow excluded from the VOIP apps, but it would otherwise offer an inexpensive contract-free way to make mobile phone calls.