www.igo.com
I use the Charge Anywhere -
http://www.igo.com/mobile-devices/ch...t/ps002730001/
It is both a wall charger and has a built in battery, so it can charge your book when there is not outlet to plug into.
It is fine on 110-115 volt outlets or 220 volt outlets. I have used mine in some 15 - 20 countries. All you need is an adapter for the outlet.
But in the bathroom, most shaver outlets will take a Euro or US plug without an adapter, so you can always charge there.