1. A computer-implemented method comprising: detecting navigation of a browser at a client to a first network address for a resource available via a resource server over a computer network; receiving an indication of at least one annotation associated with the resource, wherein the annotation is input via an annotation interface exposed via the browser; enabling via the annotation interface, selection of one of a plurality of profiles established for a user account to associate with the annotation; responsive to detecting navigation of the browser to a second network address, automatically and independent of a user selection, communicating over the computer network with an annotation server to request storage of the annotation via the annotation server in association with the selected profile for the user account and the first network address without modifying the resource.