Who owns the sky? According to Rupert Murdoch, he does: his BSkyB is challenging the right of Skype, the internet phone service, to register its name as a trademark in Europe, claiming that it is too close to its own Sky brand. Skype is one of the great unheralded success stories of the internet: where Facebook and Twitter are busy shortening attention spans and relieving us of our sense of private space, Skype has quietly changed the way we talk. That Facebook has 500 million users is well known but there are 560 million registered Skype users who have made a total of 250bn minutes of calls since it was founded, seven years ago this month.

Using it is easy: all you need is an internet connection and a laptop that has a microphone and, ideally, a webcam. When I first visited the US, 20 years ago, I would ring home by shovelling sackloads of quarters into pay phones; these days, thanks to Skype, I can talk daily to friends from anywhere in the world. Calls are free to other Skype users and cheap to everyone else. As a habitual Skype user I have become accustomed to its failings – the frozen webcam image, the metallic sound of the human voice when transported through the air, and the timelag that afflicts some long-distance conversations. There is also the sensitive issue of Skype etiquette – making business calls when still in nightwear is fine, making video business calls when wrapped in a towel less so. And yet it is still one of the few things online that has indisputably improved our lives and made the world that much smaller and chattier.