This article highlights the growing importance, challenges and opportunities of massive scale computing as they relate to libraries. Massive scale computing is defined as the predictable wide scale availability of computing power, storage and network speeds at an immense levels. The article, based on a presentation to the Association for Library Collections & Technical Services 50th anniversary conference, argues that libraries must help shape the emerging world of nearly unlimited computing capacity, and further more outlines an approach to library service in such an environment: participatory librarianship.