A cloth cover, made out of some baby clothing my nephew was not using anymore, with a rubbery foam in the back and front.
cover1: front
cover2: back, with a pocket for a small notebook and pen(cil).
cover3: cover open, with the Cybook Gen3 inside. The ring in the mid bottom is attached to the cover, and I can put a string through the hole in the Cybook's bottom left corner, and attach it to the ring, thus preventing the Cybook from sliding out of the cover. The left part is a big pocket where I keep a cleaning cloth. The ~1in flap in the left can be used to keep the whole lot closed, but I don't really use it. And yes, I should wash it
cover4: Cybook extracted, to show the nice skin.