Most digital libraries (DLs) necessarily focus on the complex issues that arise when library collections are freed from their physical anchors in buildings and on paper. Typical investigations look at supporting adults in work settings, such as school or research. Much less attention has been paid to younger generations of readers. As ever more digital venues cater to youngsters' attentions, a role for the DL as a catalyst of social interactions around traditional literacy practices begins to take shape. Based on prior research on annotation systems, constructive hypertexts, and computer support for cooperative work coupled with our contextual inquiries with children, we have developed a prototype for a digital book that supports social interactions through annotations. By placing and sharing notes, groups of readers transform the book from an artifact into a living record of communal experience. A system of support for marks and notes in the context of reading for pleasure can turn the digital library book into a "practiced place," a location that is not only accessible, but also welcoming, engaging and supportive of the activities children are interested in and therefore likely to engage in. Our experience with Alph, a prototype book-reader supporting a range of rhetorical marks and note-writing, suggests that future DLs need to look beyond augmenting work-based literacy practices by creating dynamic and social reading environments.