There are plenty of Twitter search tools out there, and here's another: Twitrratr. Here, you can enter a search term and get results back broken out in positive, negative or neutral tweets according to that topic. It works through a list of keywords, deemed positive or negative. The tweets are scanned for those keywords then placed in the appropriate category. Below you will see some results from a search for popular musicians Kings of Leon:
A positive tweet:
You can see where the words "love" and "the best" have been pulled to determine the positive rating, and it's accurate.
A neutral tweet:
Here, no words have been targeted. The subject matter is accurate, but there's no positive or negative association.
A negative tweet:
This is where Twitrratr has a fundamental flaw. You can see the negative word "wrong" but after reading the tweet it's clear that this is a positive emotion towards the subject. While there were actual negative tweets listed here too, there were several with this kind of negative/positive association. Also, Twitrratr has a tendency to pull partial words. For example, the word "will" is segmented to pull "ill" out and use that as a negative association.
So, while there are some flaws, it's not a bad tool to get a general feeling over a particular topic - music, movies and restaurants come to mind. For the Web professional this can be a great way to get an impression of how your brand is faring in the Twitter-sphere, what's being said about your brand or even your competition. It can also serve as a way to find fellow Twitterers associated with a particular industry or brand.