Tweet Topic Explorer is a new web app that creates infographics based on frequency of word use in a given Twitter stream. From their homepage:

This tool retrieves recent tweets from the given ID and displays the most common words used in those tweets.
The area of the circles is proportional to word frequency. Words that are most often used together are grouped and given the same color.

Like Wordle before it, this is an interesting way to visualize your online communications to see if the message you are actually sending matches the one you intended to send. I am particularly intrigued by its ability to group words that are used in conjunction. I can see that being useful for message development, and potentially even for SEO. For example, on our graphic the largest words are "Building" and "Product"; I was pleased to see, though, that they were closely linked to "Green", "Concrete", and "CSI".

For now these apps are primarily toys for most people, but they are informative toys and I expect they will eventually develop into useful tools.