This script simply creates a layer comp for each layer in the active document.
Download
To download this script, right-click (Ctrl-click on the Mac) on the appropriate version below, and choose "Save Target As".
								Layers to Comps
								Version: 1.1.0 (July 9, 2009)
								Download for:
								 Photoshop CS or
 Photoshop CS or 
								 Photoshop CS2+
 Photoshop CS2+
							
Note: The only significant difference between the CS and CS2+ versions of this script is the extension. Photoshop CS scripts have a ".js" extension, while scripts for Photoshop CS2 and higher use ".jsx".
Installation
								Download the script that corresponds to your version of Photoshop, and copy it into your "Adobe Photoshop CS#/Presets/Scripts" folder.
							
After restarting Photoshop, the script should appear in the File » Scripts menu.
For more detailed instructions, see the Installing Scripts section of the Scripting Photoshop, Part 1 tutorial.