The chief difference between the iPod Touch and the iPhone is that the iPod Touch lacks the cellular radio hardware and codec/signaling chipset required to make it useable as a phone, while the iPhone obviously includes these components. But that doesn’t mean there’s no way to use the iPod Touch as a phone. The secret, of course, is to use the iPod Touch’s WiFi capability to enable that Touch as a VoIP-based phone. There are currently three projects for doing so, but your results will vary
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