Web sites are increasingly adapted towards their users by a variety of dynamic techniques, providing improved personalization for the individual. In this paper we discuss various possible approaches from a museological as well as a technical point of view. A number of Web sites, some produced by museums and some in other fields such as e-commerce or Internet based information services, will be considered as case studies. All use personalization techniques in ways that could be beneficial also for the cultural sector. Other possible applications such as audio guides or interactive devices will also be considered, especially with respect to how this technique could help in the personalization of museum Web sites. Currently most museums lag well behind the state of the art with respect to on-line personalization. Perhaps this paper will inspire some museums to add personalization facilities to their Web sites the next time they undertake major updates.