Best Optical Illustion Ever.
End of the day reward: Via BoingBoing-via-RandomGoodStuff:
If you stare at the little black cross in the center of this ring of blinking purple dots, the dots will turn green and eventually disappear. But if you stare at the purple dots themselves, you'll see that they only blink off momentarily and are never green. Remarkable. Click here; watch cross for 10 seconds.