"The Remembrance Agent is one of the projects ... developed by the MIT Media Lab's software agents group. Given a collection of the user's accumulated email, usenet news articles, papers, saved HTML files and other text notes, it attempts to find those documents which are most relevant to the user's current context. That is, it searches this collection of text for the documents which bear the highest word-for-word similarity to the text the user is currently editing, in the hope that they will also bear high conceptual similarity and thus be useful to the user's current work." It "works in two stages. First, the user's collection of text documents is indexed into a database saved in a vector format. After the database is created, the other stage of the Remembrance Agent is run from emacs, where it periodically takes a sample of text from the working buffer and finds those documents from the collection that are most similar. It summarizes the top documents in a small emacs window and allows you to retrieve the entire text of any one with a keystroke."
You can still download it from this Web site (where you will also find further details about the program. It works with Emacs.
I do not use Emacs, but I am wondering whether it would not make sense in other contexts as well. In particular, I am asking myself whether it can be implemented in the context of my notes in ConnectedText. Perhaps this program is already implicitly serving this function, so the question really is whether the function can or should be made explicit, and if so, how.