I had seen data visualization of this caliber a couple of years ago.  It is the presentation of data, animated over time.  It is a very powerful way of visualizing trends in three-dimensional data that is otherwise impossible to detect in two-dimensional charts.  Consider Now, Google makes this sort of presentation freely available via Google Docs.

To get a feeling for what this can do, do the following in the sample below:

• Click the play button
• Click two or more dots to "activate them," make sure Trails is selected, then click play
• Change the variables being plotted by clicking the dropdowns along both axises and at the right

[Note to RSS subscribers: this demonstration may not work in your RSS reader and you may need to click-through to view the post on the blog site to see it.]

Read Google's Advanced Charting and Gadgets: Motion Chart for some basic info.  This could be handy for visualizing data such as poverty rates of countries over time, employee retention rates as a company grows in size, etc.  So, what other potential applications can you think of for this tool?

(Hat tip: Larry Arvan)