Soundscape:Boston
http://www.interactivesoundscapes.org/

The Software
(coming soon available for download. Only Mac&Windows. Now you can play the DEMO)
In the main screen, sounds are represented by colored dots. You can move the dot up/down to control volume and left/right to control panning. The buttons below allow you to choose new sounds, alter their pitch, or let the computer take the controls for an automated «random walk».