Timothy Butler and David Coleman have a guest editorial at Collaborative Strategies called Models of Collaboration:

• Library

The Library model provides reciprocal access to common content. The content is generally managed by a small group and is long-lasting (not time-dependent, for example). There is little or no feedback to content creators and there is generally a need for sophisticated indexing and retrieval.
• Solicitation
  The Solicitation model involves requests from a small number of requestors with multiple responders--for example, soliciting review comments or conducting surveys.

• Team
  The Team model facilitates team activities and involves most members reading and writing content, a high level of interactivity, historical information for newcomers, and document and project management features.

• Community
  The Community model facilitates the activities of communities of practice and interest. Membership in these communities is generally large and loosely controlled, although the members share some interaction or goal in common. All can participate, but generally 10% of the members do most of the interacting with the rest content to 'listen.'

• Process Support
  The Process Support model involves using collaboration technologies in a process or workflow and is used when the processes involve a lot of complexity or significant exceptions. Process support examples might include product development, training, and service and support.