The days of the plain old telephone are over.  VoIP is a new technology capable of providing voice communication over internet rather than over the traditional analogue lines.  This exciting technology brings with it the following benefits:

• Free unlimited long distance (when both locations have VoIP technology)
• Powerful PBX implementations that cost less than their traditional counterparts
• More choices for telecommunications. Until the introduction of VoIP your choices as a customer were limited to the infamously inflexible Telcom companies. Now that the industry has opened up, get ready for more power to you as a customer.
• Seamless integration with old telephone systems (you keep your phone numbers)

 

See more details from Oct 25,05 presentation to Calgary Unix User Group.