It's the revolution that has failed to happen. A couple of years ago it seemed that internet telephony - Skype and the like - were going to prove hugely disruptive to the mobile industry, ushering in an era of free calls and forcing mobile operators to change their business models.
As well as Skype, a number of services such as Fring, Jajah,and Truphone started offering apps on smartphones which, in theory, made it possible to make free calls with ease from around the world. Having tried a number of these apps myself, it's my impression that they have failed to deliver the ease of use that would make them a mass-market proposition and hence a real threat to operator revenues.
But there's one catch which could make consumers wary about mobile Voip calls - and operators all too happy to see them take off. I noticed after making a 3G call to another Skype user that two minutes online consumed over 1Mb of data. That's fine on my unlimited data plan in the UK - but would cost me £6 in the United States. Not such a great deal.
So you can see why mobile operators may resist pressure to cut international data charges. For now, internet mobile phone calls only pose a limited threat to their revenues because the sums don't quite add up for consumers - if the cost of data roaming plunges, they will become no-brainers.