This is a relatively simple, animation-ready pie chart with rounded edges. Change the Array Modifier's "Length" value to modify how much pie you want. Currently, the pie chart goes from a small slice to a whole pie. Useful for infographics 'n stuff. I set it up with Cycles render engine, easily changed.

The edges are nice and clean; the center, when you get close, can be a little messy (see screenshot). In most cases, this hasn't been noticeable (when you get further away it effectively disappears). If anyone knows a simple way to animate a pie chart that avoids this problem, please post it. Thanks!