Some clever lads at Cornell University have adapted a classic Etch-a-Sketch so you can draw with a serial mouse. Like many projects I link to, it’s not that it’s difficult, it is just interesting that someone actually did it. It also uses Atmel microcontrollers, which I prefer over the more widely used PIC chips or Basic Stamps.

I got here by surfing through GeekDIY, a site which is exactly what it sounds like. There are lots of good projects to be had there.