I just wanted to post a "review" of this plugin.
A client of mine recently called me and told me his website-admin quit and someone else uploaded a bunch of images to his site.
Of course, it was all screwed up. I had to delete all images and the thumbnails then use my plugin easypermgals to display all uploaded images of that Page.
Now we're talking about 200 photos. I didn't dare upgrade the site from 2.3.x to 2.6 (which does support multiple image uploads) because it was so heavily customized I feared I would spend days fixing all incompatibilities.
So I used this plugin to zip all the images and upload them all at once.
(don't create a ZIP with your mac ... you'll get a bunch of non-working images because of the system files your Mac OS X System just has to add to the zip)
Oh, and if you split the ZIPs into smaller pieces, it'll be faster and less prone to errors. Somehow the first ZIP with ALL 200 images didn't work.