Online Collaborative Environments are a broad term for web based sites that allow users to communicate and share work. It can be a new way to extend the intensity of what is going on in your class rooms.

Basically I see these types of tools or services broken up into two types:

  Asynchronous (anytime) Synchronous (simultaneous)
Text E-Mail Chat (MSN Messenger / AOL Instant Messenger)
Text or voice in sequence

Discussion Board / Forum

such as: Blackboard, First Class, Officezilla, Moodle

Phone based Conferencing (Voice over IP- Skype, Gizmo Project)
Groupware - Calendar Scheduling

Microsoft Outlook,

Officezilla

 
Multi-tool Environments Moodle Wimba or Yugma