Project Management – Wikis are excellent tools for managing a wide variety of project types. They provide a single place for updates on project activities, can be readily accessed by relevant people outside the organization (with permission) and provide updates via RSS to project participants. Maintaining minutes from meeting from meetings is very easily done on a wiki.
Reference material - You can use wikis to create policies, procedures, HR information, technical support information, knowledge bases, sales documentation, and so on.
Collaborative document creation – The creation of many documents involves multiple authors or reviewers. Wikis provides a simple and ready platform to enable this. Different levels of permission can be established for participants to view and update the document, and full version history can be kept to show who made which amendments, and to roll these back if necessary.
Client relationship management – Wikis, sometimes combined with blogs, can provide an easy way of ensuring that team members are literally ‘on the same page’ in dealing with the client.
Collaboration with external parties – As work increasingly happens across organizational boundaries, an array of collaboration spaces and other tools have arisen to facilitate collaboration with clients, suppliers, and partners. Wikis provide an easy tool to provide external visibility of projects activities and the ability for others to contribute, while maintaining security and control over updates.
Source: Ross Dawson