I wrote an application in Processing. A potentiometer controls the width and the height of a drawn rectangle. The application communicates through the serial port with board where the potentiometer is connected. It also send Open Sound Control messages (a colleague of mine held me to do that - he insisted to get the control data form the pot and control a synthesizer programmed in SuperCollider)

Even the fact that I am not very familiar with programming, I found Processing very easy to grasp (great community and tutorials!). The IDE was almost identical to the Arduino IDE so it was easy for me to start programming and compiling my code.

The Arduino code (for the communication):

The Processing code (draw a rectangle, communicate by the serial port with Arduino, send OSC messages to SuperCollider):

The following video demonstrates this interactive multimedia application!!