Skype

The makers of kazaa sold kazaa and then moved to making some form of P2P VOIP software called SKYPE. I'm not sure how well it works, but theres even hardware for it to allow you to interface a traditional VOIP phone, check out the Gigaset M34 USB . I wonder how hard it will be to interface to the network and build an adapter for my normal LandLine phone so I can make the computer Line#2 and make calls for free [with the use of a computer/interent] with my normal cordless phone.