Expanding / contracting text in subnav (mx or mx04)


For the site

just curious if anyone knows how to do this cool expand / contracting effect in the subnav? For example under the slide-out menu, notice the words – “advertising” – “interactive” – “design” – and “direct” These words expand and contract (with easing) when the mouse rolls over them.

I imagine that it could be done with “static” gifs or jpegs – but I’m hoping there’s a more elegant AS solution which would allow the use of dynamic text fields?