Podcasting has become popular as it allows listeners to timeâ€“shift content, i.e., to listen â€” when it suits them â€” to radioâ€“like programming on portable MP3 and related devices. Dissatisfaction with traditional radio â€” which has too much advertising and is perceived to have generic programming â€” is fueling interest in programming that better meets the individual needs and interests of consumers. Podcasting represents a shift from mass broadcasting to onâ€“demand personalized media. We look at the development of podcasting technology, the social context within which this development has occurred, and outline the legal constraints that podcasters face. Then we examine some business models for podcasting.