Another missing feature in After Effects, aside from light wrap (http://www.aenhancers.com/viewtopic.php?f=3&t=1951
), is an edge blend effect. It helps blending a foreground and a background together by blurring the edge pixels together. Here is a script that sets up a edge blend using a technique described in Mark Christiansens book "After Effects CS4 Studio Techniques. Select your foreground layer and run the script. Adjust the blurriness with the fast blur on the edge blend layer. Default is a 1 pixel blur.