Such tools could help companies pinpoint the effect of specific issues on customer perceptions, helping them respond with appropriate marketing and public relations strategies.

For casual Web surfers, simpler incarnations of sentiment analysis are sprouting up in the form of lightweight tools like Tweetfeel, Twendz and Twitrratr. These sites allow users to take the pulse of Twitter users about particular topics.

A quick search on Tweetfeel, for example, reveals that 77 percent of recent tweeters liked the movie “Julie & Julia.” But the same search on Twitrratr reveals a few misfires. The site assigned a negative score to a tweet reading “julie and julia was truly delightful!!” That same message ended with “we all felt very hungry afterwards” " and the system took the word “hungry” to indicate a negative sentiment.

While the more advanced algorithms used by Scout Labs, Jodange and Newssift employ advanced analytics to avoid such pitfalls, none of these serv