Mobile digital photography has become a ubiquitous service: nowadays, nearly every mobile phone is equipped with a camera. This results in huge collections of pictures that are hard to structure and has lead to problems in saving, managing and exchanging digital pictures. Photo- FOAF presents a new approach to mobile imaging, exploiting the social context of a picture as an important part of the metadata. We present an approach that allows users to insert social metadata in pictures while capturing them. The resulting collections of captured pictures can be managed, searched and exchanged more easily by taking benefit of the personal social relevance of a picture. PhotoFOAF implements an end-to-end process to accomplish this and it exploits, enhances and stimulates social relationships between users during all the different steps.