phpdigikam is a Web interface for browsing your Digikam photos. It allows you to quickly share your Digikam photo collection with navigation by albums or tags. You will need a PHP5-enabled server and a few lines of configuration. Features include slideshow, play movies, and re-use of freedesktop thumbnails.
tmphoto is a Web photo gallery with a fairly advanced metadata structure, allowing photos to be described in terms of place, category, persons in the photo, and events. The places, categories, persons, and events can be further described. It offers a nice browsing interface based on the metadata.