hm ok, so this feature wouldnt be useful for speed, but definitly for saving precious cardspace.
btw this background saving, couldnt this be used for the raws as well?
and have you read my post about the temperature (not color

) tags in exif? how difficult is it to add additional tags? as far as i understood exif, if your favourite image processing software doesnt know an exif tag, it is ignored. so in theory, we could add lots of tags - in theory.