(Computer telephony adds computer intelligence to the making, receiving, and mangaging of telephone calls.)
Companies and Products featuring Internet Telephony,
New Age Telcos and the like.
How to make a conference through the internet and web-based call center.
Applications that allow a person to make use of Internet Telephony, be it PC to PC, PC to Phone, or even Phone to Phone.
Voicemail, virtual phone line, internet call waiting, unified messaging systems.