Want to make your own Arduino shields? Garrett at Macetech has an Eagle file to make your life a little easier:

I created a very basic Arduino shield scaffold; the schematic has only the standard Arduino headers, and the PCB has the correct header spacing and labels. The PCB headers are locked so they can’t be accidentally moved. Also, the PCB has a dashed line showing the edge of the parts on the Diecimila board that extend higher than the female headers; if your PCB is kept behind this line, it won’t short on the USB connector when using standard length header pins.

Download the Eagle CAD project here:

(via hack a day)

Also check out Rob’s Eagle library for ATMEGA168 and ATMEGA8 microcontrollers.

And, earlier in the prototyping process, I’m a big fan of Ladyada’s protoshield kit with a mini breadboard on top.