From the website (accessed 2010-08-31):
The Antikythera Mechanism Research Project is an international collaboration of academic researchers, supported by some of the world's best high-technology companies, which aims to completely reassess the function and significance of the Antikythera Mechanism.
The project, with exemplary transparency, makes available for free download both the Polynomial Texture Mapping data of the 82 surviving fragments, and digital radiographs of all of the fragments. Computed Tomography (CT) data is not downloadable, but is available from the Project on request. High quality digital photographs have also been taken of all fragments, but seem not to be downloadable from the website.