Testing new scripts, themes, and plugins on your live site is not always smart. If something breaks, you will end up with unhappy visitors who may not return anytime soon. WordPress Sandbox is a handy plugin that lets you create a WordPress test environment for your demo site. It creates a copy of your site on your server and destroys it automatically.
WordPress Sandbox lets you limit what the demo accounts can do. You can also limit the number of sandbox sites not to overwhelm your server. You can set a reset/expiration time for your sandbox. Every time a sandbox is created, you receive an e-mail notification to stay on top of things.