Over a week ago, a WebmasterWorld thread reported that Google was testing a new form of Sitelinks. These sitelinks didn't link to different URLs, but instead, linked to the same URL but with anchors (i.e. # signs at the end of the URL, which drop you down to a section on the same web page).
I skipped past the thread, not understanding it as a new feature, until I spotted a post from Google Operating System blog detailing the difference.
For example, a search for [charles darwin] shows a Wikipedia listing with those special sitelinks, here is a picture:
The links send you to, for example, http://en.wikipedia.org/wiki/Charles_Darwin#Religious_views which anchors you down to that section of the page.
The big SEO question is, how to you get these types of sitelinks on your pages in the search results? Does adding anchor links to pages, where it makes sense, help? I assume so, but this needs to be proven.
Forum discussion at WebmasterWorld.