From World Wide Telco:
Get 30-minute free calls to 50 destinations worldwide. This pre-configured software download is designed for the Windows platform and is available in many different languages. In just a few minutes, you can start to enjoy free, unlimited calling between wIPphones with all the features of traditional phones such as Caller ID, Call Waiting, or Conference Calls, but without the cost. Receive and place calls to any regular, non-Internet telephone in the world for just a fraction of the price with our many customized calling plans and superb voice quality.