Sam Cook was nice enough to mention Junk Charts on her and Andrew Gelman's blog today. She provided another example of mischievous use of colors and shading in data maps, showing that sometimes we statisticians are no better than the rest. The effect is quite innocently hilarious and is a must-see!
Instead of assigning each level to a different color/shade, the geographical pattern of Amstat meetings is more clearly revealed if a different shade was used for 0, 1-2, 3-5, 7. Thus: