Limor of Adafruit Industries posted this video demonstrating how the Waveshield kit can turn Arduino into a sample-bending audio tool.
Consider for a moment that potentiometer replaced by - oh let's say - photocells or maybe a force-sensing resistor. If you'll excuse me - I've got some experimentation to go do - Wave Shield for Arduino
Related:

Wave Shield kit for Arduino
In the Maker Shed:

Arduino Diecimila




































