A Light wrap is a great way to have your composite “sit” better in the shot. It offers a way to have the composite look much more believable. To that end, Jonathan Lampel shows how to set up a light wrap in Blender’s Compositor.
Jonathan sets up a compositing node network that will create or simulate the light wrap effect. Adding a lighter edge to the composite will really help give the scene more realism, bringing the light and color form the background to the foreground element.
Jonathan provides the node setup for free, that you can download: http://www.pasteall.org/blend/3607