I think I have a solution for the Google images problem.
If there was a 'view entire gallery' button available for each gallery section or subsection, that showed each image on one page (with title, caption, desc, and tags), then I think Google would index those images.
The way the spiders follow links, the imagebrowser only gets a couple of images out there, while a more complete listing of the images on one page (or with <-< 1 2 3 4 >-> page links) would be indexed for sure.
This way, people could click on thumbs with the nice effects, but the listing of full or medium size images with all the text would be available to the spiders (googlebot) and sitemaps.
I'm not a php-er =( or I would do it. It seems like using the same function that displays the thumbnails could be altered to use larger image sizes, and add the title, caption, tags, etc. I think the pagination function is already there too.
I looked around to see if a solution had been found. I also looked through the Google code section to see if the issue was being worked on, but couldn't find anything. Hopefully, I didn't miss anything and this is an OK place to post this.
Alex, it can't be said enough. You rock for creating this. I hope this helps in some small way.