Use your illusion

Just picked up this link to some fascinating illusions off the SDMB. Ah, so this is why it’s so damn difficult to choose colors for book jackets—you can thank the sheer orneriness of the human brain.

P.S. I am hopelessly addicted to the SDMB. I mean hopelessly. I feel so proud of myself today, I held out all the way until 1:30 p.m. before I surfed over there!