Many thanks to Maciej Ceglowski ("lead troublemaker in the LSI revolution"); his swift response to my change requests for Search::ContextGraph means that I now have a working framework for retrieving - and persisting - document relatedness. More on this very soon. In the meantime next-generation search wannabees should check out: * The paper on Spreading Activation Search by Maciej and his colleagues. * Search::ContextGraph on CPAN * _Foundations of Statistical Natural Language Processing_, by Manning and Schultz (Amazon UK link) * Introduction to Latent Semantic Indexing * Tim Bray's masterclass series on search engine development