A GOOD EXERCISE TO KEEP YOUR BRAIN SHARP.
This will drive you nuts. The site instructions are in Japanese, so read below!
1. Touch 'start'
2. Wait for 3, 2, 1.
3. Memorize the position of the random numbers that flash on the screen, and then click the circle from the smallest number to the largest number.
4. At the end of game, the computer will tell you the age of your brain.
C/P this address into your browser and have fun ;)