Question about physics.

This is gonna sound like an extremely dumb/noob question, but please, bare with me. What’s the best way to simulate breast physics?

Take a look at my character:(she’s not completely textured)
http://freeuploader.com/view.php/102634.JPG
http://www.freeuploader.com/view.php/102635.JPG

I want her to have a little bounce, but not too much.

bones

clever weight painting

and good animation