[zackattack]

It rolls so quickly, I would find it difficult for anyone who doesn't know this to grasp the fact. It took me a second, and I'm awesome at basic mathematics. BTW, diameter here = 1.

Anyone else thought that π(n) was referring to a graph of the density of prime numbers? :P

[skolor]

It took me three watchings to figure out what they were trying to demonstrate. Between the colors (not to harp on the color blindness thing, but those color choices were dreadful) and the speed of the animation, its relatively difficult to even understand what is happening the first few times through.

[zeynel1]

I agree. The version here http://en.wikipedia.org/wiki/File_talk:Pi-unrolled.gif appears to move slower. I think it's better.