Vonage mobile app makes free VoIP calls to your Facebook friends over 3G, Wi-Fi

Long-running Voice over IP company Vonage released a mobile app for iOS and Android Wednesday called "Vonage Talk Free" that lets users call each other for free over 3G or Wi-Fi. Calls placed over 3G will incur the usual carrier data charges.

Vonage has taken a new and brilliant approach to getting customers hooked into its VoIP architecture. Instead of requiring a Vonage account to make calls, Vonage Talk Free requires only a user's Facebook account, and calls can only be made to other Facebook users with the mobile app installed on their phone. Phone numbers are not assigned, so the spread of the app will be largely done by Facebook's half billion users sharing it amongst themselves.

After downloading and installing the Vonage Talk Free app (beware, there are other official Vonage apps,) users are then prompted to enter their Facebook login information. Then, the user's list of friends comes up, and friends with the Vonage app installed will appear at the top with a Vonage logo next to their name. These are the friends that can be called for free. Other Facebook users can be contacted, but only via Facebook Chat instant messaging.

The application is currently available for iPod Touch, iPhone and Android OS. iPad supports the app, but Vonage says a version optimized for the larger screen is coming soon.