Apple websites are reporting that O2 has made a small tweak to its iPhone tariffs over the weekend, updating them to include a cost for "video calls" - which happens to be the same as for voice calls. The update lends weight to rumours that the next iPhone will come with a front camera and video calling capabilities.

It also tells us a few more things, too - it suggests that O2's rather more confident about its data network, if it expects to provide enough bandwidth for its iPhone users to start video conferencing. It also poses a question - can Apple resurrect what was once a key feature for smartphones? A few years back, every handset came with a front-facing camera, but video calling never took off.

Previous rumours have seen iconography for video chatting uncovered in the iPhone 3.2 SDK, so we wouldn't be entirely surprised if Jobs unveils the iPhone 4 to include video calling. Other rumours include a 5-megapixel camera with flash and a faster processor.

If you'd like to check out the pricing for yourself, head over to O2's Sim-only iPhone page and hit "view charges outside your allowance".

Update: O2 has got in touch with us, and said: "The iPhone section of our website states video calling is charged at the same price as voice calls. We can confirm that this was listed in error. We will be amending our website shortly to clarify this and would like to apologise for any confusion caused".

That's interesting - the only denial in there is that video calling will be as cheap as voice calling. We thought it sounded a little generous. There's no denial there that an iPhone 4, if it exists, will have voice calling.