Twitrratr
Twitrratr is a site that distinguishes between all the positive and negative words from Tweets about a subject. This is particularly good if you want to find out about the general opinion of a product or place etc.
This uses a similar concept as my news clouds project because it highlights and the negative and positive words and categorizes them. The problem with doing this through algorithms is that it cannot make an accurate decision on if the word is being used in a negative or positive way so some of the Tweets are placed in the wrong catagory. The advantages of doing this manually means that humans can make a more accurate decision about what context the words are being used in.