More than five million people have tried to escape Steve Jobs' walled garden of delights by installing Skype on their iPhone.

The application was launched on Sunday, allowing iPhone users to make Skype calls over mobile networks. Before the launch of the application for use on high-speed third generation (3G) networks on May 30, consumers could only use Skype on their iPhone when they had access to Wi-Fi.

Russ Shaw, Skype's general manager for mobile said the move was really positive with a good mix of demand across Skype's three main operating regions: Europe, North America and Asia Pacific. It is also useful as Skype plans to start charging users for 3G calls next year, so this will give it a large commercial base.

Apple is expected to announce a new iPhone on June 7. Shaw said Skype would hope to support the next iPhone too but noted that he had no details about Apple's announcement. Apple has given AT&T exclusive rights as the US iPhone provider. The Skype connection does get around this.