To get things started, we found this article via Metafilter a few weeks ago. It's from 1939 and addresses the usefulness of "useless" knowledge: http://library.ias.edu/files/UsefulnessHarpers.pdf

And a recent followup/literature review of the above: http://www.brainpickings.org/index.php/2012/07/27/the-usefulness-of-useless-knowledge/