The study takes a situated and material approach to texts and writing practices and examines writing ethnographically as it transpires and displayed in museums. The ethnography highlights the richness and sociality embodied in writing practices as well as the ideological, communal, and ritualistic functions that writing and texts serve in cultural institutions. Specifically, I offer a comparative study of visitor books and similar writing platforms in two Jewish heritage museums in the United States. Extended ethnographic observations of visitors' writing activities are augmented by analysis of visitors' texts, which, following Bakhtin, are understood in terms of their addressivity structures or whom they are addressed to. The study shows how visitors' texts amount to collective contributions that are part of museums' heritage display, and that visitors become rhetors when their mode of heritage consumption is the production of texts.