iCall

iCall provides ad-supported VoIP calls to consumers and wholesale services for businesses.

iCall is a VoIP provider offering free ad-supported phone calls to consumers and wholesale services for enterprise. From their FAQ: _All phone calls that you make to the USA and Canada are completely free, all calls that you receive are completely free regardless of where the caller is located. As well, all calls between iCall users are free._ Platforms supported include Windows, Mac, Linux and the iPhone.