The Right Brain vs Left Brain test ... do you see the dancer turning clockwise or counter-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 counter-clockwise though you can try to focus and change the direction; see if you can do it.
I saw her going counter-clockwise until Mike tried to show me that she was going clockwise… then after staring at her long enough, she started going clockwise.. and then back.. and forth.. until I could almost MAKE her turn whichever way I wanted. Does that mean I use BOTH sides of my brain? Why yes, I AM that smart* 
LEFT BRAIN FUNCTIONS
uses logic
detail oriented
facts rule
words and language
present and past
math and science
can comprehend
knowing
acknowledges
order/pattern perception
knows object name
reality based
forms strategies
practical
safe
RIGHT BRAIN FUNCTIONS
“big picture” oriented
imagination rules
symbols and images
present and future
philosophy & religion
can “get it” (i.e. meaning)
believes
appreciates
spatial perception
knows object function
fantasy based
presents possibilities
impetuous
risk taking
Source: http://www.news.com.au/perthnow/story/0,21598,22492511-5005375,00.html
*or, are the australians trying to trick us into seeing things and really the animated .gif just keeps switching between going right to left and back?
chriskalani
Thu Sep 11 2008 at 09:59 pm
I think it just depends when you start looking at it. At first I saw clockwise and then I read a little and saw it counterclockwise.
It’s easy to change the direction if you just wait until the leg is behind the other leg and then tell your brain which way to have it go.
Totally trippy.
John Lascurettes
Thu Sep 11 2008 at 10:22 pm
I’m sorry I couldn’t tell which way she was spinning. I kept waiting for her breasts to come into silhouette again.
chriskillian
Tue Sep 16 2008 at 08:32 am
I first saw her moving clockwise, then figured out that I could make her spin either direction I wanted by blinking at the right moment. Once I got the hang of it, I could tick myself into thinking she was just swinging her leg back and forth. It’s kinda creepy.
Mark Colman
Sun Sep 21 2008 at 09:16 pm
At first I saw her clockwise, then counter. Interesting thing, that.