The fractal boundary traced out by the brownian motion of the spheres in Nel's CS 444 project is basically equivalent (I believe) to a sequence of random values generated by a 1/F (pink noise) or 1/F2 (brownian noise) process. Various powers of f (Frequency) can be used and collectively are called Fractional Noise (or Fractal Noise), a term coined by Mandelbrot .
The sequence of values that make up the paths traced out by each sphere's motion can be mapped to note values in a number of interesting ways.
Playback and storage ideas:
This is a composition tool combining OpenCV Processing and PD OpenCV Blob detection and Composition
The “iPhone as Orchestra” idea is based on wireless/Bluetooth connections between smart handheld devices in proximity to one another. The first idea is implementing a master/slave architecture where the first device to begin generating a sequence transmits to all others, which employ a Pd-inspired algorithm to generate harmonization. Again, we need to start simply. Some ideas:
Other ensemble ideas using mobile devices are the PLORK, L2Ork, and iPhone Orchestras. See ,  for video clips about Stanford's experimental ensembles MoPho.
 Algorithmic composition: paradigms of automated music generation By Gerhard Nierhaus, online at Google Books
 Algorithmic Composition: A Gentle Introduction to Music Composition Using Common LISP and Common Music by Mary Simoni, online at UMich Scholarly Monograph Series and following.