Annotating and transmitting audio content items

Methods, systems, and apparatus, including computer programs encoded on a computer-readable storage medium, are described for providing content. A method includes: transmitting an audio content item that is presented to a user of a personal digital assistant through a speaker; receiving digital information that includes spoken information that was submitted through the personal digital assistant by the user and converted into the digital information, the received digital information including data specifying one or more other users with which the audio content item is to be shared; annotating the audio content item with an annotation including at least some of the digital information and data specifying that the user is the source of the annotation; and transmitting the audio content item and the annotation to the one or more other users with which the audio content is to be shared as specified by the digital information.