In the latest edition of Forbes, David M. Ewalt provides an update on P2P VoIP pioneer Skype. See http://www.forbes.com/wireless/2004/10/06/cx_de_1006telecom.html
If you haven't tried Skype yet, pop down to RadioShack and buy a PC headset for $20, then download the Skype client at http://www.skype.com. You'll be amazed by the call quality. It sounds so good, the experience seems odd at first. You feel like you're listening to FM radio, rather than your friend on the phone.
Skype launched as a free P2P service, only allowing users to call others on the Skype network through their computer, obviously not an application for the masses. However, Skype is making moves that may slowly bring the service mainstream. At the top of the list is the launch of SkypeOut, a service that allows Skype users to call any phone in the world for pennies a minute. 200,000 users have already signed up for the service. Second, is the release of Skype for Pocket PC Version 1.0, which turns WiFi PDAs into cordeless phones.
According to Ewalt, new Skype features on the horizon include 'voice mail, custom-built phone hardware including a cordless phone from Siemens and a gateway to the traditional phone network allowing users to have their own number and receive calls from outside the Skype network.'