1. A computer-implemented method of annotating pages of an electronic document independently of the contents of the document, comprising the steps of: (a) displaying a page of the electronic document on a computer display device using a document browser that permits a user to move forward and backward among a plurality of document pages; (b) detecting a selection of an annotation mode that permits the user to annotate the currently displayed document page; (c) receiving annotation stroke input from a user input device indicating that the user has moved the user input device for a continuous distance about a stroke location on the currently displayed document page; and (d) storing annotation stroke data based on the received annotation stroke input, said annotation stroke data comprising data corresponding to the stroke location and the movement of the user input device, wherein the annotation stroke data is stored in an annotation file associated with the user, the annotation file stored separate from the electronic document.