When I get the urge to create a quick screencast, I usually have a bunch of windows open and 10,000 icons on my desktop. Though I want a nice clean background for my screencast to properly highlight the content I want to capture, I rarely want to make the effort to clean up my work environment. That's where this handy little utility called "Backdrop" comes in. It's so simple that I can describe what it does in a single sentence:

Backdrop covers your desktop and windows with a colored background, effectively cleaning up your workspace without moving a single icon or closing a single window.

Here's a quick screencast (made with Screenflow) that illustrates the app:

Backdrop is donation-ware and is available at http://www.johnhaney.com/backdrop/.