The MetaArchive Cooperative has released A Guide to Distributed Digital Preservation.
Here's an excerpt from the announcement:
This volume is devoted to the broad topic of distributed digital preservation, a still-emerging field of practice for the cultural memory arena. Replication and distribution hold out the promise of indefinite preservation of materials without degradation, but establishing effective organizational and technical processes to enable this form of digital preservation is daunting. Institutions need practical examples of how this task can be accomplished in manageable, low-cost ways.
This guide is written with a broad audience in mind that includes librarians, archivists, scholars, curators, technologists, lawyers, and administrators. Readers may use this guide to gain both a philosophical and practical understanding of the emerging field of distributed digital preservation, including how to establish or join a network.