TECHNOLOGY WATCH: Reading Hidden Text with X-Rays (Peter Gurry, ETC). A good reminder of (Peter) Head's Rule: "the best place to find unknown manuscripts is inside known ones."
Also, Drew Longacre, at one of those text-critical blogs noted in the immediately preceding post (OTTC: A Blog for Old Testament Textual Criticism), has more on the possible application of x-ray technology to manuscripts: European Genizah" and X-Ray Technology. More on the "European Geniza" is here and links.