Lauren has a nice article on blogs and wikis on the Gilbane website Blogs & Wikis: Technologies for Enterprise Applications?.
Blogs and WIKIs are real knowledge management at work. Add in a change-control repository with sane URLs (like CVS with ViewCVS or Subversion for the new generation). Then add a mailling list manager with sane URLs like GNU Mailman...What have you got? A powerful set of tools for knowledge management, collaboration and information integration that use URIs the way the Gods intended - persistent, semantic identifiers of resources.
On top of that, build your Web appplications using URIs the way fate intended with RESTian principles and what have you got?
...Pretty much everything you need quite frankly.