Halfbakery.com is a site where people can submit inventions and ideas (no matter how wacky), others can comment on it, and annotate it with link references and images. In addition, thumbs-up (bun) and thumbs-down (fishbones) functionality allows users to rate each other's ideas, and it works very well.
You can click on a user's name to see all of their other ideas, and you can browse similar ideas within the category. Best of all, there are many ways to search the ideas and comments by various criteria, and subscribe to RSS feeds of searches.
It is like what you are doing here, which I'm happy with, but with a little more functionality. It is a good model to follow.
Voting on Ideas
Vote for your favorite ideas by clicking on the up arrow.To undo an upvote, simply click the arrow again. This second click removes your vote.