The October 5 release of the new Vonage Mobile application marks the Internet calling provider's foray into new markets, enabling the US users of the Apple iPhone and the Research In Motion (RIM) BlackBerry to make international calls using Vonage's Internet-based technology.

The launch of the new Vonage application would further enhance the use of the Apple mobile platform in the enterprise arena by opening the door to new functionality, thereby deviating from Apple's much-criticized preferential treatment towards AT&T.

The simplicity of use of the Vonage Mobile application is evident from the fact that it is all set for use once a user goes through with a rather quick download and registration process.

Not only does the application support an interface fairly akin to the iPhone's native phone call interface, but it also bases its service on the users' existing iPhone numbers, instead of assigning them a new phone number.

Vonage, which is a Wi-Fi service, provides $1 in calling credit to each new sign-up, and updates the users' amount of credit left on the application's console - giving the users the advantage of refreshing and adding calling credit pertaining to their usage of the service.

However, about the application, the company cautions the users that the Vonage service is "not a replacement for your ordinary telephone service and you cannot make emergency calls using Vonage Mobile."