This is on the WashingtonPost.com site and is pretty interesting. The issue tracker “includes information from the Web sites of a wide variety of sources across the political spectrum. Sources include news organizations, political parties, interest groups, bloggers, unions, trade organizations, candidates, activists, and more.”
Run your cursor over a face and see the issues that are revealed. Click on a candidates name to see how many comments come in on what issue. Click on one issue and see how that is divided among the candidates.
This is a good visual look at what people are talking about.