Yesterday a change to the iPhone SDK allowed for VoIP over 3G and we heard about the first app which'll offer the functionality. Today another iPhone app, Fring, has begun allowing video and voice calls using Skype over 3G.
You don't need to update your version of the Fring app as it was simply a matter of Apple lifting some restrictions on its end. You can now freely make Skype calls without being connected through Wi-Fi - assuming you've got decent reception. [Fring via Pocket Lint via Engadget]