PHP photo galleries

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.