From Bonnie Covel:

"I've created this action for making double page layouts into two single, printable pages. Digital scrapbookers don't know they need this, but once they have it they will wonder how they ever lived without it. At least, that was my experience with it. I love actions!!!"

About the Double to Single Page Layout Action:

Use this action in Photoshop to quickly transform double-paged layouts into two single-paged layers in order to print, while preserving your original double-paged layouts.

This is a time saver if you create your layouts in double-paged spreads. This action creates single-page printable layers for layouts in the following sizes:
12 x 12
8.5 x 11
8 x 8
6 x 6

Note: The action was created and tested in Photoshop CS2. It may not be compatible with earlier versions of Photoshop.

Step One:

Download the Double to Single Page Layout action.

Step Two:

Load the action into Photoshop. (Instructions for Loading Actions)

Step Three:

Save your current double-paged layout or open a new double-paged layout. The layout will close at the end of the action, so be sure your layout has been saved.

Step Four:

In the layers palette, click on the print size of the layout you are working with and click the "play" button. Or push the keyboard key that corresponds with your layout print size:
12 x 12: F5
8.5 x 11: F11
8 x 8: F8
6 x 6: F6

Step Five:

Sit back while this Photoshop action quickly does your work for you.

Step Six:

Print your layouts. Your original double-paged layout closes automatically in exactly the same state it was in the last time you saved it.