this is a video demo of the rig I have created.
It is a ball and tail rig to practice squash & stretch, timing and spacing and follow through and overlapping action.
I have updated the rig for 2.5.6 but the video shows the 2.5.3 version. Nothing has changed in the rig itself but you can hide the visibility of the 3d view and the render separately.
here is the rig:
there are more rigs here:
feel free to use the rig for what ever purpose he wish - you do not need to credit me, but can if you like.