Disruptive VoIP player Skype has announced at Mobile World Congress that its eponymous VoIP application will be integrated on Nokia N97s from Q309.

The application will be integrated into the device’s address book and be visible to users as a mobile widget. Making the announcement both Scott Derchslag, COO, and Josh Silverman, CEO of Skype highlighted the success that Hutchison’s 3 has had with its fully integrated Skyphones. Since launch 500,000 Skyphones have been sold and users make one million, free, Skype to Skype calls every day. Over three quarters of all 3 Skypephone customers are new to Hutch.

There are, of course, a number of differences between today’s Nokia announcement and the very successful 3 project. First and foremost, today’s announcement does not include a carrier. As Durchslag noted, “a number of cracks have appeared in the walled gardens, we need to see the walls come down to make Skype Everywhere a reality.”

Therein lies the chief obstacle Skype faces in trying to reach mobile users. Carrier inertia on removing barriers to the full mobile internet remains strong. Josh Silverman: “There is a symbiotic relationship between the people who provide the networks, devices and applications. As we move forward people are expecting phones to get more like computers than phones. ARPU on the 3 Skypephone is 20 per cent higher than the next best. So, not only is it their most popular phone, it is also their most profitable.”

That there is a convergence between the mobile and internet world is undeniable. As Silverman noted communications is moving from a hardware business to software business. During the week prior to Mobile World Congress, consumers  in the UK and US were given access to a new VoIP offering from a firm called Vopium. The service is easily downloadable, like Skype, and enables consumers to make long distance calls at domestic rates by routing the call over IP networks. Unlike a similar offering by Truphone users do not need to dial in a separate number.