From the MAKE Flickr photo pool
Instead of relying on the usual project wiring, Kris designed a custom Arduino shield for controlling an LED light bar. He was also kind enough to document the ins and outs of his process –
After many months of working on my Arduino based project, I decided to finalize my project by making my own custom PCB. At first I wanted to design a PCB that connected to the Arduino through a series of cables. After some thought however, I realized that a shield would be better because it would eliminate the need for cables.
DIY Arduino Shield