Good photo of those Concrete octagon tiles that sky found online installed. They could look really great in the bathrooms. Maybe with a different tile running up the walls half way as pictured or even just continuing the wood wainscoting into the bathrooms. Then perhaps finding a great wallpaper for the upper half of the walls.
I like this idea but could it look like Tetris? How cool would that be?
2009 Residential Winner: Frank Lloyd Wright School of Architecture. Tiles: Floor Gres, Etruria Design & Edilcuoghi
How cool is this modern, subway-tiled bathroom? 20+ more bathroom layouts here: http://www.bhg.com/bathroom/color-schemes/colors/bathroom-color-schemes/?socsrc=bhgpin072414blackyellowwhite&page=3