1. A method of annotating digital content comprising steps of: creating an annotation related to a portion of a volume of digital content and storing the annotation in computer-readable memory in a manner that maintains a logical connection between the annotation and the portion of the volume of the digital content, the annotation being created by a first user; creating a comment in response to the annotation and storing the comment in computer-readable memory in a manner that maintains a logical connection between the comment and the annotation, the comment being created by a second user; and displaying the portion of the volume of the digital content together with at least an identification of the annotation and at least an identification of the comment.