Spot [neoformix.com] by Jeff Clark is a comprehensive real-time Twitter visualization that uses a particle metaphor to represent unique tweets.

According to a set of user-defined keywords, the visualization gathers and displays the latest 200 tweets. The according particles are then organized in various spatial configurations to visually filter the available information by different parameters, such as: commonality of words, according to time, according to people, or categorized by the actual tool that was used to send the tweet.

The tool also allows to explore the tweets from a specific list, such as the “Top 100″ of the datavis community, for instance.

More detailed information is available here.

See also Revisit and Digg Labs Swarm. Alternatively, check out Visual Digg Explorer by the same designer.