The User Behavior Ontology has a home – http://ubo-ontology.org/
During the last year, we developed an ontology to capture user behavior in an application independent format. The result is the UBO. We first tested it in the SERUM project to build short and long term user interests profiles. Currently, we integrate it in our delicious clone DAIKnow. Additionally, we developed an RDFa based tracker to collect the user interaction on websites. As the tracker is not fully stable, we currently keep it behind closed doors. As soon as it is ready for the wild, we will open source the tracker.