Semantically-enhanced Ubiquitous User Modeling aims at the management of distributed user models and the integration into ontologies to share user information amongst adaptive applications for personalization purposes. To reach this goal, different problems have to be solved. The collection of implicit user information by observing the user behavior on dynamic web applications is important to better understand the user interests and needs. The aggregation of different user models is essential to combine all available user information to one big knowledge repository. Additionally, the Semantic Web offers new possibilities to enhance the knowledge about the user for better personalization.