What is UC?
Microsoft has a better way:
use software

Microsoft unified communications technologies bridge the divide between computers and telephones with two integrated servers: Microsoft Exchange Server 2007 and Microsoft Office Communications Server 2007. They integrate with your company's existing phone system and deliver complete communications services using your existing data network.

No forklift required: Microsoft unified communications technologies maximize your existing infrastructure by integrating legacy PBX systems through a VoIP/PBX gateway.

With Microsoft unified communications technologies, the computers on your network gain the functionality of advanced VoIP phones. Users can click to call any contact in their address book. A simple phone call can become a conference call or a video conference, on the fly.