Goto CNN.com (you can even try it here on Anthology Creative). Then copy & paste the following line of code into the address bar:

javascript:document.body.contentEditable='true'; document.designMode='on'; void 0

Hit Return. You can now edit the page freely. Select some text, change the copy, drag and resize the images.

See - Anthology Creative was just featured on CNN’s homepage:

Bummer that you cannot add your own images or move full block elements around, but it is a nice way to trick friends and family - if only to act as if you hacked CNN.com.

This trick works on any website.

Just as a sidenote: this trick does not actually allow you change the public page, so you will only see the changes in your browser.