One of the first apps I got for my iPhone was Tango. I had seen it used by several friends who were unwilling to jailbreak and use Facetime over the 3G with Cydia Top Ten App called My3G. The app allows you to use Apple apps that they would have you only use over Wi-Fi on your 3G Data plan. Yahoo.
So I use Tango off and on when talking to the kids or any other number of friends. I like the app and it always seem relatively stable. (enter AT&T network bashing rant here) In any case, the makers of this fine app called Tango have gathered on to them, a small fortune “which will enable the company to deliver faster on its product roadmap” as well as release a new product to their range, Tango for your Desktop PC!
Currently Tango for the Desktop PC is only available for Windows and will cost you a whopping free. It will be available in the next few weeks and you can sign up on the Tango website for an advisement of when it goes live.