Tweet Sentiments is mesmerizing, as it analyzes sentiment on the twitter feed. It uses OpenAmplify's Natural Language based Semantic Analysis engine to measure the positive (or negative) emotions associated with tweets. Watch as tweets roll by at a rate of 1 per second with the sentiment shown in red/yellow/green icons. Also has pie charts, gauges, and trending topic lists with associated sentiment.

I have been seeing more than a few articles lately about the use of Semantic Analysis, specifically Sentiment Analysis, in predicting stock market changes. Moods can move markets and tracking moods online may give the tracker an advantage in stock picking.
What do you think?