Mask Animations

Hi guys,

I had a question and I was hoping someone here could help me out. I’m trying to do an effect very similar to the effect that is happening at the beginning on the flash animation on this site:

At the beginning theres a short frame with some verbiage and after that there is a transition of a 3 with an image mask. The 3 expands and revealst he image behind it. Anyone know of a tutorial on how to achieve this effect? Thanks!