Ikea Besta units - I love the idea of a complete wall of units.Could be used in any room including a kitchen or playroom. The glossy finish reflects light back into the room and would hide a multitude of clutter.
add wood wallpaper to the kick plates of the stairs. Those rolls are expensive but you would only need one. Not practical with white treads though, it will be stuffed up from black shoe soles in no time.