Nice, longer article on hosted VOIP as an efficient means to unified communications.
How To Get Going Fast With Minimal Cost? – Hosted Services!
Fortunately, because IP Telephony is now software-based and accessible over the Internet, it has joined other business process applications in becoming easily available as a hosted or managed service that can be used to replace or supplement legacy premise-based TDM telephone systems and call center technologies. IP Telephony service is labeled as “Communications as a Service” (CaaS) and is becoming a key starting point for hosted UC services.