If you are interested in getting the most out of your iPod and you enjoy the DIY culture, Will O'Brien has posted How-To: Design your own iPod super dock (Part 2). In this part of his ongoing series, he takes you step by step through designing a schematic for the "Super Dock" in EAGLE. You can grab EAGLE Light Edition for OS X here (note: requires command line installation). I also posted about Part 1 of the series on TUAW.
The upside of this series by Will is that you can freely expand upon what he has started. Use your imagination! Do you need to have an iPod dock that is integrated into your home brewed robotic kitchen? Will your car benefit from custom iPod controls on the steering wheel? Can your pet have its own playlist control functions at home with interactive carpeting? Will lays the groundwork for you and lets you be your own Griffin or Belkin engineer.