Just upload the script to a server, add a bunch of folders with your photos in them. That's it!! The folders become categories, and you can start browsing. No database set up or anything like that. Highly customizable modular architecture w/ CSS based templates and PHP "tags" (functions) as well as a few cool options like: randomizer, slide show, extended info (EXIF and IPTC caption), thumbnails and list view, etc...