I’m just adding a little color to Mike Bostock’s demo.
Mario Klingemann has made some beautiful Voronoi diagrams. This is my attempt to recreate them using D3. To achieve the curved cells, each side of the Voronoi polygon is subdivided into three equal-length segments and then joined using the “basis-closed” line interpolator. There are some discontinuities in the animation when the sides of a polygon approach zero which could likely be avoided by adding a minimum-length threshold to the subdivision.
If you’d like to see other instances of this pattern, Mario describes the algorithm on Flickr.