I learned several months ago that 2 studs wide is equal to 5 plates high.
Seeing as I've wanted to build a calibration cube for my computer vision
project, I've been thinking of ways to exploit this.  (Actually, I was
embarrassed to learn this since I knew that 6 studs wide = 5 bricks high
and I just hadn't done the math.  DOH!)

Finally, I figured out if I made each face 6-2x2 tiles on an edge, I'd have
a nice shape for calibration.  Of course, then I had another challenge.
How do I make this thing using SNOT.  As you'll notice, every side is studs
facing out for the middle 4x4.  If you look closely, I've got 2 panels that
are 12studs x12studs x5 plates and 2 panels that are 12 studs x 8 studs x 5
plates and the final one that is 4studs x 4studs x 5 plates.  So now, I've
got my cal cube, a cool desk ornament and a little hiding place all in one
project.