Mr. Oyvind from Oslo sent us a cool hack of a 75-years-old radio into an iPhone dock using an Arduino.
On his website you can read the complete tutorial or download the code and below you can have more details on the way he used the board:
the Arduino is used to read the state of the dual potentiometer that controls the volume and then translate this value into a certain number of LEDs being lit on the volume indicator.
I am using a Duemilanove. The code for the project is very simple and can be found here: http://www.build-electronic-circuits.com/wp-content/uploads/2013/05/radio_ino.zip