AMHERST, Mass. - Imagine being able to store 25 full-length, DVD-quality movies on a disc the size of a quarter. That amounts to a data storage density of about 1.2 trillion bits per square inch. A recent development by University of Massachusetts researchers may someday enable consumers to do just that. The research is detailed in the Dec. 15 issue of the journal Science, and is funded by a National Science Foundation "Partnership in Nanotechnology" grant, the Materials Research Science and Engineering Center, and the U.S. Department of Energy.