Well, i used a Solio for mine. Its not perfect, but it works, since the iLiad needs at least 9V to be charged. And you need the Travel Hub and the car charging unit in between. I havent found any pins for it yet, that could be directly be plugged into the travel hub.
Soli o- german Solio - Homepage
Could be interesting for Reader users, since it comes equipped with a usb plug. Will see if it works with the cybook aswell.