We use an "HP Officejet 150 Mobile All-in-One" printer.  It was expensive, but it is very compact and fits on the small shelf we have to the right of the navigation desk.  It is battery powered (like your computer) so it accepts 110-240V and 50-60Hz.  It also will let you print wirelessly from your laptop.  It's small enough to put in your backpack and take with you in a pinch.