Backdrop is a Mac OS X only Freeware app.  Backdrop turns your Mac into one giant, blank screen of distraction-avoidance.

Whether you're taking screenshots/making a screencast and you want a bare background, or you prefer to work with as spare a workspace as possible but you can't bring yourself to keep your desktop clean, Backdrop is a great tool. Just start it up and it automatically places a layer over your desktop and all your open apps.  Color of your background is your choice.

Backdrop Features

• Fills your screen with a color or image

• Take screenshots with a clean background

• Supports multiple monitors

• Use Backdrop in between applications to allow you to focus on one thing at a time

Installation Instructions: 

Copy Backdrop to a desired location on your hard drive (may I suggest the Applications folder).  Open Backdrop from your hard drive to enjoy.

Note: Not copying to your hard drive and running from a disk image may cause Backdrop to crash.

I have it installed on my Mac and it works perfectly!

Mac World gives Backdrop a 4 Mouse rating!