If you're planning to travel this upcoming holiday season, make sure you install the InvisibleHand browser plug-in before you start booking your trip. InvisibleHand is a free money-saving tool that helps you find the lowest prices on hotels, flights, and rental cars. Once you download the plugin for Firefox, Chrome or Safari, InvisibleHand hides away until you start shopping online. If it finds a better deal, it self-activates and shows the better deal at the top of your browser (just like in the image above). Download it today to start saving money on travel!