This is some code for explorations into multi-sensory expression. Check out this post for some details: The Color of Music
Lots to be developed but if you're feeling adventurous and wanting to hack...
The code under color_follower will run in just the regular Processing environment.
The code under us_audio_color_follower will require an arduino, the arduino programming environment, 4 wires, an ultrasonic sensor, an a breadboard to tie it all together. Both the arduino and processing code are in the folder.
Hack away. Express yourself. Enjoy. :)