In this paper we claim that the new generation of Web-based systems should offer an intelligent, flexible and interactive support to their users, coupled with the ability to provide personalized solutions. We think that problem solving techniques could be exploited to face this challenge. In particular, we present STAR, a Web-based system that exploits the configuration technology in order to support a tourist in organizing a personalized agenda for a tour in a city. We describe the system architecture and the knowledge representation supporting this task. A first prototype of STAR is being implemented and it is instantiated on the city of Torino (Italy). KEYWORDS Adaptive Web Systems, Intelligent Agents, Internet Services, WWW/Internet Applications, Web Personalization.