1. A method for using a computer system to provide additional material related to a concept within electronic text, comprising the steps of: a) identifying material for display in association with a request for display of non-prespecified related electronic text; b) providing an indicator of said material for display; c) and in response to execution of computer-executable code included in said electronic text, display of said indicator, and selection of said indicator, transmitting said material for display to the requestor of said electronic text, wherein: i. said code is formatted and designed to be executed in real-time without user action when electronic text including said code is displayed; ii. when executed, said code causes a computer to submit a search request for additional information related to a concept represented within at least one text section of said electronic text, said search request leading to a search of an index, said search of an index identifying additional material related to said concept; wherein: A. said index contains a plurality of terms by which it may be searched; B. at least one term in said index is associated with a plurality of references, at least two of said plurality of references each providing information sufficient to specify different material; C. said index search yields information sufficient to specify said indicator of additional material; and D. said indicator comprises display material not derived from said electronic text; and iii. as a result of execution of said computer code, said indicator of additional material for display is provided for display in the same presentation as said electronic text.
18. The method of claim 1 , wherein said code, when executed, includes user identifying information as a search parameter.