First of all - I really like the fact that Picasa doesn't change
anything in my original. I only take raw images and they tend to be
rather large, picasa have the tools needed to adjust the pictures and
the resulting jpeg is mostly sufficient for my needs.

So, what I would like is a way to tag images so I could export the
originals (all backup files in the Originals subfolder belonging to
the image displayed in picasa)  to another disk, (some backup media)
and free up space on the disk where the rest of my images reside.

This way I could tag images gradually and when the collection of
tagged files was large enough I could export the originals off the
disk.

The way I do it today is that I take a copy of the entire picture
folder - to another disk, then delete the image from within picasa,
and finally copies the jpeg back into picasa and the image is
rescanned. The problem here is that I also loose all the album links
for the image I delete and all these must be recreated for every
image.
It works but it is not the picasa way :-)

Also - if using tags for this "export original" feature it would be
possible to also store the guid used to identify the image in the
album, effectively giving us an easy way to import the original back
into the picasa library, where we could reprocess the image if that
was required.

Thanks
Svein