MUSE (standing for Museums and Sites Explorer) is an experimental mobile multimedia system for cultural settlements. The system is based on a hand-held computer connected to a site control center by a wireless link. It provides interactive learning and entertainment to the visitor, as well as site monitoring and control functions to the management. Thematic visits with virtual access to physically unavailable items are supported. During the tour the visitor can create his/her personalized multimedia memory that can be emailed or saved on a CD to be collected at the end of the visit. The system provides logistic information; for example alternative routes may be dynamically suggested to the visitors in order to avoid congestion and increase the sustainable site fruition level. The system is user-centric and its interface supports self-orienting on the site while encouraging unexpected discoveries and experiencing of CH based emotions. Several information technologies cooperate to narrow the gap between the cultural items and the public. Specifically the system relies on emerging data models, on the integration of state-of-the-art software technologies and on next generation tablet computers. The intended hand-held device should combine its low weight and low power requirements with nearly PC-like 3-D rendering capabilities. The paper discusses the main design issues, as well as the conditions that should be met to turn this class of experimental systems into a real industrial product.