An Israel based fringland Ltd. is a privately held mobile application developer company, who recently launched a free application called the "Fring".Its a mobile voice over IP application that allows you to make free mobile calls and send instant messages. To put it the other way, you can make free call via your mobile through Fring. How ?.. well through internet via the 3G/Wifi network. so you see no airtime/talktime required.
Fring also seamlessly integrates with Skype, Google Talk, MSN. To start with.. all you need to do is download the fring mobile software from the website on your mobile. All simple instructions are very well mentioned on the Fring site. Click here for the website http://www.fring.com/
You could check out the below video, where the application is demonstrated LIVE. Enjoy and post in your comments.