We've picked a white and light blue pinstriped tile for the shower walls; these are tiles that we've custom ordered from Italy (we ordered this stuff months ago - 10 weeks lead time from Italy!).
We're also using quartzite squares (4 x 4) for the floor of the shower and in larger scale (12 x 12) around the medicine cabinets. The contractor was originally planning to build a cantilever bench (~ 1 foot deep x 2 feet wide) using a quartzite slab, but apparently quartzite doesn't come that big (either that or it is prohibitively expensive. I wasn't paying too much attention when my wife was explaining this part). So the contractors are framing a bench block that will be covered in quartzite tiles (if my math doesn't fail me, the bench tiles should be 7 x 3 ... or 8 x 6 ... whatever. I tend not to sit too much in the shower, anyway).