I recently spotted this handy little tip at blogstorm.co.uk.

Ever wanted to edit the text of a web page to create an annotated screenshot or mockup? Simply paste this line of code into your browser’s location bar, and voila, the page text can be edited:

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

No, you it doesn’t enable you to edit the original page. It does, however, let you easily alter your local copy.

Handy, eh?