7. A method for associating an electronic document work with an action, the document work comprising text, the method comprising: a) electronically extracting within a portable client device features from the electronic document work; b) transmitting the extracted features from the portable client device to one or more servers; c) receiving at the portable client device from the one or more servers an identification of the electronic document work based on the extracted features, wherein the identification is based on a non-exhaustive search identifying a neighbor; d) electronically determining an action based on the identification of the electronic document work; and e) electronically performing the action on the portable client device.
8. The method of claim 7 , wherein the identification is based on a non-exhaustive search identifying a neighbor within a fixed radius.