Network-Activity-Chimes is a project mainly written in SuperCollider, it's free.
Gives you auditory feedback on your network bandwidth usage by playing light chimes
Mac OSX only right now, sorry This program requires SuperCollider, Python, and top.
The supercollider code is in Network Activity Chimes.app/Resources/SCClassLibrary/modifyStartup.sc It starts a python script that reads the network activity and cup usage from top, and writes it to nets.txt 10 times per second.
supercollider then reads this file to determine the parameters that control the synth