I found Stan Garfield's description of Knowledge Advisors at HP to be a great definition
"Knowledge advisors perform the following tasks:
1. Help users learn about and use the available people, process, and technology KM components. Provide consulting on processes and tools.
2. Facilitate collaboration. Connect people to others who can help them or whom they can help.
3. Direct users to the right knowledge sources based on their specific needs. Locate relevant knowledge resources.
4. Assist users in searching for content and knowledge. Find reusable content.
5. Actively offer assistance to work teams. Engage by contacting users, not just waiting for requests to arrive.
6. Review content submitted to repositories for compliance to quality standards, and follow up as required to improve quality.
7. Solicit user feedback. Direct feedback to the right person within the KM team.
8. Conduct training. Create and record self-paced courses.
9. Search for information to help meet deadlines. Send search results to users who are not connected to the network.
10. Network with other knowledge advisors. Back each other up. Help respond to requests. Take over open requests at the end of the work day based on being in different time zones."
Stan also published a report by Knowledge Street "Advisors at Hewlett-Packard: Connecting People with Information" that provides insight to the mix of people, technology and process.
It is the mixing of these three that are the core of a knowledge management project.