Techniques are described for managing various types of content and devices, such as via a user interface of a Content Management (“CM”) system executing on a computing device. In some situations, the content being managed includes television-related programming content and/or other types of content (e.g., one or more channels of scheduled digital music and/or on-demand digital music, photos and other images, etc.). In some situations, the content managing is performed via a mobile device (e.g., a smartphone or other cellular telephone, PDA or other electronic organizer, etc.) via a CM system user interface displayed on the mobile device, such as to allow a user of the mobile device to access some or all of the functionality of the CM system that would otherwise be available via a CM system GUI displayed on a general-purpose personal computer, as well as to synchronize with such a GUI in various ways.