First create a new layer, and make it the size and proportions you want it. Second, animate the vertical scale of the layer (uncheck the proportional link) to your liking. Third, duplicate the layer four times, and move the dupes to where you want them on the screen. Done. If you want the animation offset, then change the layer spacing on the timeline.
Joe Bourke
Owner/Creative Director
Bourke Media
http://www.bourkemedia.com