Tthe Microsoft
RoundTable (now sold by Polycom as the CX5000) is the primary supported video conferencing device for OCS for use in meeting rooms. Otherwise workstations can use any type of Webcam device to support video. There are some certificed for OCS devices, but almost any built-in or USB camera will do the job. Take a look at the Webcams tab on this page for a list of certified devices:
http://technet.microsoft.com/en-us/office/ocs/bb970310.aspx
Jeff Schertz, PointBridge | MVP | MCITP: Enterprise Messaging | MCTS: OCS