CLE: 
Voice Over IP Phone Systems
"An IP (Internet Protocol) PBX (Private branch exchange) is a business telephone system designed to deliver voice or video over a data network and interoperate with the normal Public Switched Telephone Network (PSTN)." (Wikipedia)
Voice over IP is one of the most significant technologies to mature over the past few years. Taking the place of traditional PBX systems, a VoIp PBX can provide many additional features for a significantly reduced cost.
Features:
- Automated Receptionist
- Logging and Reporting
- Hunt Groups
- Remote Extensions
- Advanced forwarding
- Bridged branch offices
- Much more...
Savings:
- Shared Infrastructure for telephone and networking
- Reduced long distance rates
- PBX can be installed on generic hardware
- Unlimited extensions
- Easy scalability
- With softphones even handsets can be eliminated!