This slideshow retrieves photo information from 23 via RSS and Google AJAX Feed API. It includes a quick and dirty function to get a bunch of meaningful object info about every photo in the RSS feed, and then there's a few lines to make sure that the slideshow keeps going.
Remember that this is only a demonstration of the 23/rss/photo/google/... options. If you want to include a slideshow on your web page, 23 do this for you much easier. Just go to any given tag, album, story, and so on and click the "Share on the web" link.