Where can I find the gray linen texture that's used as the Lion login screen background?

My company just updated to Lion, and I really like the gray linen texture that's used as the initial login screen background. I'd like to use it for my desktop background, but it's not one of the options in the Desktop preferences (in the Apple section, anyway.) I'm assuming the graphic exists somewhere, and if I know where I can choose it from the folders.

Can anyone tell me where this graphic is saved or what its filename is?

The dark linen source file is stored in the System Library folder so you will need "root" or administrator permissions to make changes to the directory or the file.

/System/Library/Frameworks/AppKit.framework/Versions/C/Resources/NSTexturedFullScreenBackgroundColor.png

1. Open System Preferences » Desktop and Screen Saver:

2. Click the "+" at the bottom left:

3. Press Command + Shift + G to bring up the "Go To Folder" menu, and paste in the path to the background image:

   /System/Library/Frameworks/AppKit.framework/Versions/C/Resources/NSTexturedFullScreenBackgroundColor.png
   

   (Press Go, and then Return when you see the NSTexturedFullScreenBackgroundColor.png file is selected)

4. You will now be back at the System Preferences window. Make sure that the drop-down selector is set to 'Tile'

Voilà!