Twitter Sentiment makes reading the pulse of the Twittersphere a breeze. Enter any term or word, the default right now is NBC Olympics, and get graphs and recent tweets on the mood about that topic. You will get a percentage pie chart, a number count and the words used. Enter your own term and simply click submit.
Below that a zoomable graph of the last week shows the trend with counts. You can scroll back and forth in date ranges as well as zoom into a specific date and time range.
The bottom allows you to see tweets with the token words from the top, good and bad words on the topic, with a data range selector. This is a great tool to use around an product launch and major event to get the feeling of the population.
Anyone trying to see the heartbeat of what they are talking about as a company or conference, this is a great starting point.