There is a Switch screen saver slideshow available [download]; it was created from an Apple demo and features eight switchers. After you've downloaded and uncompressed it, put it in ~/Library/Screen Savers/. If you control-click on it, you can copy the switchers and use them as a desktop background. The slide show was created using this hint. Enjoy!
Mac OS X Hints
http://hints.macworld.com/article.php?story=2002092606125920