Check out this script Ease and Wizz I just stumbled on.
http://ianhaigh.com/easeandwizz/
Types of easing
Regular easing (from most to least dramatic)
Expo, Circ, Quint, Quart, Quad, Sine
Special types
Back, Bounce, Elastic
I have not used it yet myself but
I think it might be just what you need.
Looks very cool-
-Andy