fring? is a 3G mobile application that allows you to make free mobile calls and send instant messages (chat) to other fring users(mobile/desktop PC) and PC based VoIP services such as Skype and Google Talk.

fring? enables mobile-to-mobile calls, mobile-to-landline calls, and mobile-to-PC calls including integration with Skype and Google Talk (Full-duplex voice quality).
Sadly, the app is currently available for Nokia S60 2nd Edition devices like N70, 6682, 6630, 6680 and N90. Currently, the service is in Private Beta.