For providing synchronization of image data among diverse devices and applications, exemplary systems include a direct client application providing a user interface operable to allow a user to organize image data according to albums, and to select one or more albums for synchronization with one or more server interfaces that provide various image data manipulation, sharing, and features related thereto. Systems also include an intermediary system to assist in synchronization of select albums with handheld devices, and a notification server to provide scalable notifications of album updates made at server interfaces by users. Exemplary methods include steps providing for selection, from direct client applications, of albums to synchronize with devices, including handheld devices, and various steps of providing updates and notifications among appropriate system components.