Alex_TJ - 1:10 am on Mar 2, 2010 (gmt 0)

We have a FAQ page that's over 3000 words in total, and so the 10 FAQs are by default hidden on load with CSS:none and then modified by javascript to show on user click.
G did a lot of crawling of this page and it took over a year for it to rank well on an established site (though that also coincided with the addition of self-referring links between FAQs, which rank excellently) but is now doing well without problems.
I've noticed that Microsoft has started using these collapsable divs in their Knowledge Center articles, though vice versa with hide on click.
One thing I haven't tested however is a system to have search terms highlighted and that div open when referred from a SERP - I haven't figured that out technically yet, though seems to work well on this site.