If you’ve got a Windows Mobile 5 or Windows Mobile 6 phone you can use Fring to make VoIP calls and live chats via multiple sessions and clients, such as MSN Messenger, Skype, Google Talk and several others.
Though most of the basic services will be free, outbound calls to real phone numbers will still incur a fee.
Depending on where you are in the world you may have trouble using any kind of VoIP. T-Mobile asserts that it isn’t blocking Truphone calls to a large spectrum of UK customers, and that these numbers just happen to be Truphone numbers.
T-Mobile claims that Truphone’s termination rates are simply too high, whereas they’re willing to work with Fring and Skype.