Natural-looking wave/ OS X dock effect

I’m starting my first Flex project, and I need to develop an OS X - style dock navigation with a slight wrinkle: the dock background should have a subtle wave effect that follows the growing of the icons.

I found this site, which has a fairly exaggerated version of how the backrground should flow:
http://www.toto.co.jp/

Has anyone run across anything like this? My mind is cramping from the math involved.