While this post is a little late for Christmas, shopping never goes out of style and neither does getting a good deal. InvisibleHand is one of those tools that can save you money while you are browsing the internet.
InvisibleHand is a browser plug-in for Apple Safari, Google Chrome, Microsoft Internet Explorer, and Mozilla Firefox. It also works on Windows, OS X and Linux. If you are on a site that has pricing for a product, InvisibleHand will start working in the background and if it finds pricing from other web sites it will notify you how your current site compares.
Tom's Tech Tips 