Someone recently pointed me towards Tacit Software as a company I'd be interested in. Their team has created a system to automatically catalog expertise within an organization. The question they're trying to answer is 'Who can I ask about X?', and the goal is to prevent redundant work within an organization. They have an interface where employees can ask a question, and the software will try to identify the best people to answer it.
They offer two different products, Illumio which is based on a desktop client and ActiveNet, which is centrally deployed. Illumio works a lot like a desktop search system, analysing all the files on a user's computer including documents, emails and contacts, to identify areas of expertise. ActiveNet is similar, but looks at the data stored globally on the organization's servers to figure out who knows about what.
One interesting approach they're using to demonstrate Illumio's potential are the public web groups they've set up. To join, you download Illumio and it analyzes your interests. You can then participate in their groups to ask and answer questions on topics ranging from sports to business.
An area they've obviously spent a lot of time on is safeguarding users' privacy. The process they use for answering questions involves getting permission from the people it decides are experts on the topic before any identifying information is returned to the questioner. Privacy is a big concern, but this does seem a bit unwieldy compared to the Knowledge Network approach where experts pre-approve what information is going to be exposed, and it's then available for easy browsing and searching by other employees.
Their case studies show they've deployed in some large organizations and report some impressive satisfaction figures. Their descriptions of hotspots where they see a lot of redundant work are illuminating too, they've focused on procurement, research and new project proposals. This definitely fits with my experiences, though I've spent most of my time on the research side.