I’m looking for a file- or MySQL-backed PHP photo gallery that allows
you to tag photos for later searching (maybe like del.icio.us?), as
I’ll be tagging pictures with topic as well as photographer. Most
image galleries seem to be strictly hierarchical (if not flat).

I’d like it to automatically create thumbnails, too. I hope
http://www.ipowerweb.com has gd or imagemagick. If not, I’ll just have
to do the image uploading and tagging myself…

Useful: http://php.resourceindex.com/Complete_Scripts/Images_and_Graphs/Image_Indexing/

The description for http://www.snipegallery.com/ mentioned being able
to search by keyword, so I think I’ll go for that one.
Gallery (http://gallery.menalto.com)
also looks useful.