Windowless bathroom? Have no fear! Consider this nifty idea of using a window as a shower door. Of course, it's not as good as an actual window because it won't be admitting natural light into the room. But this is a close second for its other window-ly qualities of adding architectural interest and bouncing light around a bit:
In the three examples shown, steel-framed, industrial-style windows have been used in place of your typical shower door. In the first two examples, actual windows were salvaged for the use. In the third, the shower door was custom-designed to look like the rest of the casement windows in the house. Pretty cool detail, isn't it?
Images: Spaller|Glover, Glass Works of Summit, House Beautiful