<i></i>This paper proposes a Mobile Multimedia Library (MML), a new application of information retrieval using camera-equipped mobile phones. MML allows users to get information of an unknown object anywhere and anytime. A user simply takes a picture of the object by a mobile phone and sends it directly to an MML server on which the picture is analyzed to identify the object. The MML server returns the identification result to the mobile phone and the user can browse information of the object on the display of the mobile phone. This application employs the <i>k</i>-Nearest Neighbor approach using eight MPEG-7 visual features to identify objects. A prototype system for animal identification has been developed to demonstrate effectiveness of the MML framework. It takes about ten seconds on average for the identification in which 63% and 79% queries were correctly identified within first four and first ten candidates, respectively, out of 229 categories.