Here is an absolutely fascinating data visualization of Eurozone debt. Although I don't know if this is written in Processing or not, I have learned enough these past two days to tell you it would be fairly straightforward to do so.
Data visualization brings together the computer science and the generative art solidly. It isn't just about making pretty pictures. In order to create meaning and relevance in your visualization you need to manipulate, perhaps transform, your data. Depending upon the application, this could mean pulling in calculus, trigonometry, geometry, physics, and chemistry. It could mean creating well thought out OOP code, efficient threading and algorithmic selections, array manipulation, random number generation. Another one of the workshop leaders, Deepak Kumar, showed us a class assignment where students must use an array of Objects to create a row of streetlamps (any design they want) that randomly turn on and off.
We experimented with creating code that behaves like those art boards where you paint with water: as you draw lines/shapes with your mouse they fade behind you at whatever rate you dictate.
Web interfaces, network communication, digital audio generation. One of our workshop participants expressed an interest yesterday in working with sound in Processing - today we were listening to her computer broadcasting music from across the conference room.
If you are interested in using Processing in your classroom, the workshop leaders (Deepak Kumar, Dianna Xu, Ira Greenberg) would be happy to talk with you.