One of the headline features of the new iPhone 4 is undoubtedly FaceTime calling, Apple's take on video calling technology. It's certain to be a hit with your iPhone-loving friends, but will it also hit your wallet? No, is the simple answer from Apple. At least, not initially.Apple has made it clear that any use of the feature will not drain the 'free' minutes of your contract. Why? Well, initially, it will run only over a Wi-Fi network. Coupled with use of the service being free as well, the cost to you, will be a big fat zero.There was some confusion because of the iPhone 4's ability to switch, mid-call, from voice to video, but speaking to BusinessInsider, a spokesman for Apple said: 'The voice call ends as soon as the FaceTime call connects. The FaceTime call is over Wi-Fi so does not use carrier minutes.'So enjoy all those free 'face' calls while you can, because charges are almost certainly going to arrive sometime, especially when the service extends to 3G. That will offer up far more freedom for the service, but with it the temptation to hammer those inclusive minutes when you're bored at the bus stop.