The field of invention is computer-implemented systems and methods for creating and transmitting media to mobile devices, and in particular, methods and systems for locating, selecting, grouping, and arranging media items in playlists, and transmitting playlists to mobile devices and / or other electronic devices. This invention enhances the usability of mobile devices, and in particular, the usability of any mobile phone by making a user's media or third party media accessible to that user via the mobile phone. An object of the invention is to make any mobile phone a personal media player such as a “MP3 player”, a “Podcast” player, a “slideslow” viewer, and so on.