"We absolutely expect our vendors"--Apple, in this case--"not to facilitate the services of our competitors," he says.

"Skype is a competitor, just like Verizon or Sprint or T-Mobile," he says, adding, Skype "has no obligation to market AT&T services. Why should the reverse be true?"

Meanwhile, Apple has remained mum on the matter, though it's easy to see why the company might not want to get involved. After all, being able to use VoIP over AT&T's 3G network could help Apple sell more iPhones by providing another attractive feature--but, at the same time, Apple doesn't want to risk alienating their business partner.

The U.S. isn't the only place where VoIP restrictions are irking customers. T-Mobile, Apple's wireless partner in Germany, has said that not only will it prohibit use of VoIP applications on their 3G network, it'll also and cancel the contract of any customers who try to work around the restriction.

In response, the Voice on the Net coalition, which includes Skype, as well as Microsoft and Intel, has and enact policy that would protect consumers rights to choose what applications they can use.