Recent progress in digital photography and storage availability has drastically changed our approach to photo creation. While in the era of film cameras, careful forethought would usually precede the capture of a photo; nowadays, a large number of pictures can be taken with little effort. One of the consequences is the creation of numerous photos depicting the same moment in slightly different ways, which makes the process of organizing photos laborious for the photographer. Nevertheless, photo collection organization is important both for exploring photo albums and for simplifying the ultimate task of selecting the best photos. In this work, we conduct a user study to explore how users tend to organize or cluster similar photos in albums, to what extent different users agree in their clustering decisions, and to investigate how the clustering-defined photo context affects the subsequent photo-selection process. We also propose an automatic hierarchical clustering solution for modeling user clustering decisions. To demonstrate the usefulness of our approach, we apply it to the task of automatic photo evaluation within photo albums and propose a clustering-based context adaptation.