How would I do this? (link inside)

This link is to one of the OpenLaszlo demo’s.

Enter the store and use the slider to adjust a variable (“age range” or “price range”). The products that don’t fit into your filter are no longer viewable. This is the easy part, I know how to do that (make the slider control a variable and make every product’s mc base it’s visibility/alpha on that var).

Here is the part I don’t know how to do. After you’ve adjusted the slider and caused some of the products to no longer be visible, mouse over one of the remaining products. This will cause all the remaining products to reposition and scale themselves. This is the part I’m trying to replicate.

[edit] Here is another example from the adobe flex site.
Click on products, then play with the filters and the phones will scale and re-align themselves.[/edit]