Cool - just downloaded it - will take a look this afternoon.....
When I first read it, I thought it was something similar to a script that I'm working on at the moment, but then realised that it does have it's differences...
If you're interested in seeing the results of my script, then take a look at:
https://www.unframedstudios.com/maya/ears.avi (650k DivX)
https://www.unframedstudios.com/maya/tailTest.avi (770k DivX)
It generates motion down the chain from the 'control joint' at the root. The initial idea was to do something that would automate a rabbit's ears - although I then realised that it would work well with tails as well.
If you want to have a play with an early beta of the script, you can download it from:
https://www.unframedstudios.com/maya/createEars.mel
Source the script, select the first joint that you want to be dynamic (there MUST be at least one parent joint) and run startCreateEar();
Have a play with the UI settings - the defaults are currently the ones that I found worked best for the ears....
There is still a lot of error checking missing, so please don't try to break it - you will find it very easy to do!