Apple set itself a real challenge with the iPhone 4, by making video calling – the great white elephant of 3G – one of the device’s main advertising points. And if FaceTime, as Apple rebranded it, isn’t crippled by history, it is certainly challenged by the fact that it only works over wifi. Until now that is, but it’s not Apple that has brought video calling to the cellular networks.

Voice over IP player Fring said Friday that its latest app brings two way video calling to the iPhone 4 over the cellular 3G network as well as wifi.

Because Fring also allows its uses to talk among themselves regardless of device, the updated app effectively enables video calling between users of iPhone 4, Android and Symbian S60 devices.

Fring has also enabled multitasking on the iPhone app, so it can run in the background, and has improved its integration with social networking tools and the address book.

[youtube]http://www.youtube.com/watch?v=bUaFaKApPX4[/youtube]