Phone calls over the Internet

• pc-telephone.com/  -  http://www.pc-telephone.com/
  Full-on voice over IP software that allows PC-PC or PC to Phone conversations. The PC to PC calls are totally free whioch is why its listed here.
• Speak Freely  -  http://www.speakfreely.org/
  As the name implies, this software is free and allows free voice of IP calls. Difficult to set up, but works well once you've got over the initial hurdle.
• Voice Weaver  -  http://www.voiceweaver.com
  text and voice chats with members of your website, all done via an ActiveX control. Sounds very useful, if you run a membership based website and want your members to chat to each other.