HelloSoft, Inc. is developing various VoIP Technologies for mobile devices, they have recently announced the launch of its VoIP technologies for mobile devices based on Symbian OS. Over 110 million Symbian smartphones have shipped worldwide to over 250 major network operators.

HelloSoft has taken one of the first of many steps to enable VoIP technology globally for the next generation of Symbian smartphones.

HelloSoft’s VoIP technology, HelloDual-Mode(TM), on Symbian OS will allow users to experience award winning power-efficient and fully-featured multi-mode applications.

You can read more about it here http://hellosoft.com/pressroom/pressrelease/press_04_04_07.pdf