Growing integration of Web 2.0 techniques by museums is indicative of their readiness to redefine their relationship with their audience. Where visitors were traditionally kept at arm's length, the use of these techniques now involves them at every stage in implementing the museum offer on the Internet. From an inductive perspective and through an extended examination of various sites and tools offered by organizations, this article aims first to highlight the different roles currently devolved to the public in terms of communication, mediation and artistic creation. It then goes on to analyse the ramifications of visitor involvement. If these tools are able to develop the audience competences and to make museums less stuffy, their implementation may also induce tensions by challenging their authority and legitimacy and by disenchanting their visit experience.