I found Fritzing a few days ago and have been having a lot of fun with it. This free software/website combo allows you to easily create great looking electronics illustrations. It can handle pictures of the actual parts (like an Arduino and a bread board), schematics, and even PCB layouts.
I’ve decided this would be a great program to use for making illustrations for SproutBoard. Fritzing comes with a bunch of Arduino graphics but the SproutBoard is unusual in that it mounts an Arduino upside down. Nobody else does this so I had to make the graphic for it from scratch. It was surprisingly easy! Fritzing uses SVG graphics so I was able to create the image in just a few minutes using Inkscape. I plan on making custom parts for the SproutBoard as well, but those will be a bit more complicated so it’ll be a while before I finish them.