Consumer uses of mobile devices and electronic media are changing. Mobile devices include increased computational capabilities, mobile broadband access, better integrated sensors, and higher resolution screens. These enhanced features are driving increased consumption of media such as images, maps, e-books, audio, video, and games. As users become more accustomed to using mobile devices for media, opportunities arise for new digital watermarking usage models. For example, transient media, like images being displayed on screens, can be watermarked to provide a link between mobile devices, extending the reach of digital watermarking. Digital fingerprinting can also be employed. Applications based on these emerging usage models can provide richer user experiences and drive increased media consumption. A great variety of other features and arrangements are also detailed.