With the development of social networks, it has been increasingly easier to make friends on the Internet. However, it may not be as easy to automatically find a friend with "similar interests". In this paper, we develop a novel system that allows users with similar interests to be quickly introduced based on the similarity of pictures they took. A real online system, named Friendbook, is implemented on a smartphone network. Due to the limited resources on a smartphone as well as privacy issues, instead of directly comparing the original pictures for similarity measure, Friendbook uses "feature-based" picture comparison. By comparing features extracted from pictures taken by people who want to make friends, their similarity in interests can be automatically inferred based on the content of these pictures. We refer to friends made through Friendbook as "S-friend" for "Semantic-friend". The system also demonstrates the difference between S-friend matching with geographic-based G-friend matching.