FlashBack is a peer-to-peer backup algorithm designed for power-constrained devices running in a personal area network (PAN). Backups are performed transparently as local updates initiate the spread of backup data among a subset of the currently available peers. Flashback limits power usage by avoiding flooding and keeping small neighbor sets. Flashback has also been designed to utilize powered infrastructure when possible to further extend device lifetime. We propose our architecture and algorithms, and present initial experimental results that illustrate FlashBack’s performance characteristics