Yes, we have met with Continuum and other reps of companies that are producing and selling CD-ROMs of images of art works in museums and private collections. Museums may be selling the rights to digitized image reproduction to companies like Continuum but most, if not all, are not selling exclusive rights. That is, the copyright owner retains the right to resell the image, etc. I have written this without double-checking but believe it essentially correct. And, as most probably know, museums and private collectors do not always own the copyright to all works in their collections.