1. An electronic device, comprising: a display for presenting paginated digital content to a user; and a user interface including an annotation mode, the annotation mode including multiple different note types for paginated digital content, the note types comprising: i) a sticky note that can be created in response to a tap or mouse click or selection made on the paginated digital content when the annotation mode is invoked, wherein the sticky note is represented by a movable graphic and selection of the graphic causes contents of the sticky note to be presented; and ii) a margin note that can be created by converting a previously created sticky note to a margin note, such that the margin note replaces the previously created sticky note and includes content from the previously created sticky note, wherein contents of the margin note are always presented and the margin note is configured to be placed anywhere on the paginated digital content.