This is very flattering: Greg Houston took my script for DIY canvas pie and added tooltips and better colors logic. Here's the result, it's really nice, built with some MooTools. The tooltips are not supported in <canvas>
but Creg used an image that overlays the pie and set the tooltips with an image map. Clever, isn't it?
I just used random colors for the pieces of the pie, but Greg knows better. Based on a tutorial by Jim Bumgardner, he was able to achieve much more pleasing, yet reliable results. Funny thing that Jim works in Yahoo! two floors above me (used to be even on the same floor).