Ghost in SketchUp Plugin Pro Comp 2013 helps in generating scenes with large number of components without the scene being heavy. GhostComp, created by Fredo6, helps in associating simplified version to a component, called Ghost. The script offers a simple way to switch back and forth between the Ghost version and the Real version in the model.
The main concept behind it is that in many situations, switching complex and heavy components to their Ghost version would make the model view lighter to operate during the design phase for copying, orbiting, etc. The plugin is free can be downloaded from Sketchucation.
GhostComp uses a hidden layer to maintain copies of the original components and their Ghost versions. It is important to note that GhostComp does not touch, modify or delete the original components.