Aside from the expanded use of XML and XSL, there are some other things I'd consider for the photo-journal I publish.
First, I hadn't really considered just how long it takes to read everything, let alone look at all the pictures over a slow network connection! The download times are acceptable, but when everything is added up along with the time to do the reading, it's hard to imagine anyone getting all the way through in one sitting. (Heck, it took me five days just to proofread it.) With that in mind, it would have been nice to use browser cookies so that readers could quickly be brought back to where they left off the last time they visited. (Bookmarking is okay, except for the extra, unintuitive steps you need to take when viewing via frames.) And as long as I'm introducing cookies, I might as well make full use of it and start collecting statistics on the browsing capabilities of visitors; site statistics are great, but none can tell me what screen resolutions people are using, or whether they have JavaScript purposely disabled.
The JavaScript code - while thorough - could use a lot of cleaning up. Before I was done, I had put in kludge after hack after kludge, resulting in a rather delicate architecture right now. For instance, to determine what day and chunk is currently being viewed, I look at the URL of that page, rather than set global variables and examine them. Lots of "special cases" exist for dynamic labels (titles, footer text, links, etc.) to handle pages that aren't part of the progression of days, like the introduction, epilogue, list of links, and these technical details. All of this needs serious purging, and maybe a substantial rewrite.
I actually did some reading up on PHP around midway through my development effort. I began thinking that it might have been nice to use that, instead of server-side includes, but learning curve notwithstanding, it took my ISP about a month to set it up for me, and I didn't feel like losing any more time, having put in about four months already. It also didn't help that I had nothing but grief trying to get that to work on Apache/NT, too (although, admittedly, I did give up pretty quickly). Next time - perhaps - I'll try my hand at PHP, so there'll be one more technology to add to the arsenal!
As a final note, all of the code I've put together for building this site (at least most of it) is available to fellow web developers, if you wish to create your own photo-journals in the same fashion. Feel free to your request, and give me some time to put things together and document them. I ask in exchange that: 1) you mention where you got it, and 2) you share any improvements with me, so they can, in turn, be shared by others as well. But don't let my email wind up in any search engines, okay? :-)