Something that would be immensely useful (for certain applications of course) would be the ability to reference meta-data of the save. Author, Last-Edited, Ect. If it were a unique datatype that couldn't be spoofed with a table or such, it would also be super useful for securing any webrequest functions as well. Heck, even just adding a flag to the webrequest to automatically send the current file's meta-data would be amazingly useful.