Via Daily Kos, there's an image here (or here) which is supposed to reveal if you are predominately a right brained or left brained person:

THE Right Brain vs Left Brain test ... do you see the dancer turning clockwise or anti-clockwise?

If clockwise, then you use more of the right side of the brain and vice versa.

Most of us would see the dancer turning anti-clockwise though you can try to focus and change the direction; see if you can do it.

The first couple times I glanced at the dancer, I initially saw her turning counterclockwise. But in subsequent tests I've seen quite a bit of clockwise rotation. So the results are mixed. Other tests I've taken suggest I'm left brained. Sometimes I think both sides are malfunctioning.

More on brain division here.