As small digital cameras become more popular, opportunities to take photos are rapidly increasing. Photo sharing is a great way to maintain and revitalize relationships between families and friends, and is a major motivator for content sharing. While photo sharing has been well studied, little work exists on sharing multiple photo sets contained in spontaneously connected handheld devices. This paper provides an algorithm to extract photos, based on common memories collected in an ad hoc group. It automatically searches for and presents photos that could become the starting point of a conversation. We found that our mechanism has more uses than simply organizing photos in chronological order. This paper describes our prototype system realized using the above algorithm. We also implemented a synchronized shutters mechanism, that provides a new photo sharing experience. Through subjective tests, we found that our method promotes conversation, even though the users did not know each othe...