Some programs, like noise ninja, strip all the exif data out of jpgs. So I’ve looked at some exif editors that have the ability to batch process a folder of pre-noise processed jpg files, pull the exif data out of all of them, and then add it back to the corresponding noise-filtered files.
You could also use an exif data editor to add data to your files, such as gps location, personal notes, copyright information, particular lens used (rather than just focal length) etc.