Thanks for the comments. I'm trying to make a 3/4 head turn only with bones and actions, The idea and setup is taken from heyvern's work, so I hope he doesn't mind.
@ ulrik: No bone dinamics, only rotation. You can see in the picture that there are only two bones (vertical) that give movement. The horizonalt one is for rigging the ear and for the translation of the other bones. The horizontal one is fundamental to perform turning with bones and actions...
I have to put a tip & techniques post about some things I have discovered about bones binding and action combination.
Genete.