1. A method for sharing notes associated with a document on a computer system, the method comprising: creating, by a first user, notes associated with a location within the document by linking the first user's notes to a portion of a table to contents of the document that reference the location within document, wherein the notes are associated with the document and stored on the system; receiving, at the system, a request from a second user to share the notes created by the first user, the second user's existing notes associated with the same document stored on the system; designating access rights to the second user to share the notes created by the first user, the access rights defined by the first user when creating the notes, the access rights specifying a time constraint on access to the first user's notes by the second user and permission for one or more access types given to the second user for accessing the first user's notes; inserting, by the system, the first user's notes into the second user's existing notes associated with the document in accordance with the access rights designated to the second user, wherein inserting includes accessing the table of contents for the document, identifying page locations within an instance of the document provided to the second user and referenced by the portion of the table of contents linked to the first user's notes, the instance of the document provided to the second user also comprising the second user's notes linked to portions of the same table of contents, and enabling display of the first user's notes at the identified page locations, within the instance of the document provided to the second user, that are referenced by the portion of the table of contents linked to the first user's notes; and notifying the second user of the availability of the shared notes, thereby allowing the second user to retrieve the shared notes.
1. A method for sharing notes associated with a document on a computer system, the method comprising: creating, by a first user, notes associated with a location within the document by linking the first user's notes to a portion of a table to contents of the document that reference the location within document, wherein the notes are associated with the document and stored on the system; receiving, at the system, a request from a second user to share the notes created by the first user, the second user's existing notes associated with the same document stored on the system; designating access rights to the second user to share the notes created by the first user, the access rights defined by the first user when creating the notes, the access rights specifying a time constraint on access to the first user's notes by the second user and permission for one or more access types given to the second user for accessing the first user's notes; inserting, by the system, the first user's notes into the second user's existing notes associated with the document in accordance with the access rights designated to the second user, wherein inserting includes accessing the table of contents for the document, identifying page locations within an instance of the document provided to the second user and referenced by the portion of the table of contents linked to the first user's notes, the instance of the document provided to the second user also comprising the second user's notes linked to portions of the same table of contents, and enabling display of the first user's notes at the identified page locations, within the instance of the document provided to the second user, that are referenced by the portion of the table of contents linked to the first user's notes; and notifying the second user of the availability of the shared notes, thereby allowing the second user to retrieve the shared notes. 14. The method of claim 1 , wherein: the access rights defined by the first user vary as a function of social connectivity of a requesting user; and inserting the first user's notes into the second user's existing notes in accordance with the access rights comprises determining a social connectivity of the second user and filtering the first user's notes for insertion based on the determined social connectivity of the second user and access rights defined by the first user for the determined social connectivity.