From the awesome name, to the genius idea, to the real-life benefit, InvisibleHand is the add-on I talk about with friends. While shopping for a pair of nylons (yes, nylons, I don’t change my story just for you guys) on Overstock.com, InvisibleHand popped up to tell me that the same product was available on Amazon.com for $3 less. Nylons on Amazon? Who knew? Me, thanks to InvisibleHand.

Once you install InvisibleHand you’ll see a welcome page that explains the basic functionality of the add-on. As you look for products on popular shopping sites like Amazon, Buy.com, and Overstock, a yellow bar will appear at the top of your screen whenever InvisibleHand finds a better deal for your item. For example, when you try shopping for nonstick cookware on Overstock, InvisibleHand shows 4 competing offers that translate to 18% in comparative cost savings.

Unless it finds a deal, InvisibleHand will stay “dormant” as a gray arrow in the bottom-right of your Firefox status bar.

InvisibleHand is a relatively new add-on that is working to expand the number of retails stores and countries it supports. At the time of this post, the add-on was working on a total of 115 retail sites in the US, UK, and Germany.

So, whether you shop a lot or a little, InvisibleHand is an add-on to try if you’re looking for a better deal.

Post from Elise Allen, who is still waiting for Adam Smith (and Warren Buffet) to accept her LinkedIn invitation. See all posts by Elise Allen.