Here's another use case perspective: consider the webcomic. There's a case where you're not searching for something—that is, every single "page" is possibly valuable content—but there's still hundreds, potentially thousands of pages to display.
The problem comes in when someone is looking for that one comic they saw a few years ago. Unlike xkcd, this comic hasn't implemented full-text search yet, so if they can't do a manual comparison sort, they have to go over every comic. What's a natural way to do this?
Still new to web development and user interface design in general; this is probably a different problem altogether.
I think that the solution is right there in your question — full-text search. xkcd takes this to an extreme perhaps, but even just transcribing the text in each comic ought to be enough to make it decently searchable. That and titles. I can usually get to an xkcd via the title or some words similar to the title which are usually in the comic itself. This may not work for comics which tend to be visual gags though.
If it is too much of a pain to manually transcribe the text, perhaps using OCR?
For a lot of things, a huge spatial visual index would be more useful than the text. Microsoft had some sort of project where you could have several thousand photos onscreen at a time. An analogous case from the physical world would be searching for a particular image you remember from a thick book of artwork. I think this would be pretty easy for most people, but I don't know of a good digital version. Maybe the xkcd archives would be a good testbed.
Allowing the comics to be tagged (perhaps invisibly) by users to facilitate search could be another possible solution, that could be easier than OCR and also include non-text specifics.
Usually when I remember a comic and am trying to find it, I remember one specific detail, whether it's a picture or text.
The problem comes in when someone is looking for that one comic they saw a few years ago. Unlike xkcd, this comic hasn't implemented full-text search yet, so if they can't do a manual comparison sort, they have to go over every comic. What's a natural way to do this?
Still new to web development and user interface design in general; this is probably a different problem altogether.