In addition to tracking social media, many search engines provide the capacity to track trends in the use of search terms. Google, for instance, provides access to current trends as well as the ability to track term usage over time (or at least back to 2004) for general usage, as well as in terms of news references. Yahoo, Bing, AOL, Twitter, and YouTube all offer similar services. Many of these also can provide user information in aggregate, and can be further broken down by geographic location.
Online metrics firm Crimson Hexagon recently provided a demonstration of some of its Online traffic tracking services though an analysis of the reaction to the Supreme Court's health care ruling. They posted some screenshots of their real-time analytic platform ForSight that provided both descriptive summaries and more qualitative analysis of themes expressed through social media.
As I said at the beginning, the online world's providing a lot of interesting ways to quickly capture and analyse public opinion, comments, and reactions. Get to work, folks.
Source - Healthcare Ruling Sparks 12,000 Tweets Per Minute, Mashable
What People Search For - Most Popular Keywords, Search Engine Watch
Obamacare: Online Reaction to SCOTUS Ruling (Update) Crimson Hexagon press release