Expert Finder - Finding Experts on some field of knowledge to assist you with problems you might have. Trying to build user communities and leverage knowledge from these.
Users can send messages to each other asking for assistance.
Collaborative Ontologies - Communities building and defining ontologies to be used by systems as their needs show up. Tools to allow the experts to define new classes and relationships between these to suit their needs. Context Sensitive Agents - Agents that monitor your activities and try to extract knowledge from that. Defining user's expertise profile is an example. Let's Browse - Collaborative Web Browsing.