If you have a login here, you might have recently been playing with pudge's beta test of expandable AJAX comments, with all the weirdness and user-interface strangeness that entails.
Generally, it's been good so far, but I just realised one enormous benefit.
It means that by putting all the data on one page, Google and other search engines are going to be extremely easily able to index entire message including comments, which would have previously been lost.
I only realised this today, when a Google search turned up a use.perl journal post based on content in the comments.
On that basis alone (of exposing more content to indexing) I wonder if it is worth looking at this sort of Ajaxification for all sorts of comment systems. Or at least the sane ones anyway.
I haven't looked too closely at what's going on, but I didn't think it used AJAX. If it did, then when you clicked to expand a comment, there'd be a round trip to the server to get the comment text.
I think the way it works is that the full text of the comments is included in the page (good for Google as you say) and client-side JavaScript is used to show/hide bits.
Re:Not AJAX, Just Client-side JavaScript
pudge on 2006-07-19T06:34:13
Right, not Ajax for that, although long comments do require Ajax to fetch the rest.
Google doesn't have access to the DHTML comment pages (yet?) though.
What we do have (in part, not finished) is OAI (Open Archives Initiative), which is better... but it requires special hookup with Google or Yahoo or whatever.
If you could get the Googlebot to crawl the pages with ?mode=nested
appended to the URI, that would work just as well.