[UPDATED: Wednesday, November 26, 2008 at 8:41:22 AM]
I just noticed that Google appears to have added some new features to the results page. The new features are buttons for "Promote", "Remove" and "Comment".
The "Promote" feature appears to be a way to give your "thumbs up" to content—which I'm sure will affect the rating of a page and thus affecting SEO. The "Remove" feature appears to be the way to report a bad link (like a Black Hat attempt, or just some general spam page.) Lastly, the "Comment" feature appears to be a way to add a comment about a page.
This new feature is part of Google's new SearchWiki. I think they must be selectively releasing this functionality, because I'm not seeing it every browser on my machine—so it's either cookie-based or browser-based.
UPDATE:It appears all you need to do is log in to Google in order to see the SearchWiki features. Logging out will turn the feature off.
Here's a video that talks more about SearchWiki: