Transition effects

Hey everyone.

I'm trying to recreate an effect to have a similar outcome.

Go to this site:

http://www.si03.com/thesite.htm

Notice the start of the animation, the transition effect that expands the menu, heres a ss:



I've fiddled with photoshop, i've used flash, i've done many a thing, but for the life of me i cannot reproduce even anything that resambles the desired effect, i have a good hunch that the key lies in Liquify filter on photoshop, but theres no simple way to do this...

Is there some sort of software that makes these types of effects and export to gif or fla? Any recommendations?

Adobe After Effects