Ulrich Schmid of the INTF just announced in a comment to a previous post that a database version of the Kurzgefasste Liste der griechischen Handschriften des Neuen Testaments (ed. Kurt Aland) will be published on-line soon, perhaps by the end of September. This will allow fantastic new possibilities of doing simple or advanced searches among the catalogued MSS, including, for example, new search fields with information like "exemplar of" and "copied from." New information on individual items can be added continuously, I suppose under editorial supervision.
We very much look forward to this on-line tool!