We examine the ‘native’ metadata and organizational structures that individuals create for their personal photo digital libraries, by analyzing the behaviour of photo collectors as recorded in 37 autoethnographies and ethnographies. The findings confirm several common assumptions about how people organize their photos that have been the basis for features in earlier photo digital libraries- that photos are commonly organized by time, event, and location, and that collection owners create very little metadata manually. We discuss alternate sources of metadata that arise as a consequence of sharing photos, and consider additional features for photo digital libraries that may be useful in supporting searching and browsing of personal collections.