I like Tricasa... :-)
Thanks for the compliments everyone. It's got a long way to go... there needs to be AJAX for getting and submitting comments, as plain JS possibly adds too much to the initial page load... and it needs to be able to load individual images, and work with back/forward in the browser.
The code is fairly simple... it should speak for itself, but if anyone wants explanation I'd be happy to give it. It took a couple late nights, followed each by a morning where everything made much more sense. ;-)