1. A method for associating a document with a data structure, comprising: displaying the document at a graphical user interface; selecting at least a portion of the document; creating a data node; displaying the data node at the graphical user interface; at the graphical user interface, graphically moving the selected portion of the document to the displayed data node; in response to graphically moving the selectable portion to the displayed data node, associating at least the selected portion of the document with the data node; receiving node identifying information, for identifying the displayed data node; and receiving tagging information for the displayed document, for identifying the displayed document.