This is one of the most soothing and amazing videos on YouTube. Look at this musical instrument made by hand and played with marble balls.
I remember posting about the AxiDraw on an earlier version of Doobybrain but I never followed the progress of this custom hand-writing robot and had no idea that the company behind it, Evil Mad Scientist, was on version 3 of the device.
For $475, you can create works of art with all sorts of writing tools without even putting in the effort. And if you do a lot of repetitive writing tasks (like signing your name or addressing envelopes), you can turn that tiresome process into an automated one with the AxiDraw V3!