De-linearize skin weights with easing algorithms. This tool is part of the rjSkinningTools.
Copy the rjSkinningTools folder to your Maya scripts directory:
Delinear weights applies an easing algorithm to the skin weights. This tool is best used if skin weights have been copied from a low polygon source, when this is done sometimes it is very obvious that the weights are linearly divided between the vertices of the low polygon source. This tool will tween those weights.