Comparing KitchenAid stand mixers with a single click from Target's Web site works well.

Like it or not, the holiday shopping season is upon us. Luckily for those of us who dread the thought of wandering through crowded malls and department stores with Christmas music assaulting our ears at every turn, this nifty little tool called the Internet is here to help save our sanity. Still, scouring dozens of Web sites for the very best deal on that perfect gift is exhausting on a whole 'nother level. To that end, Superfish--a visual search engine developer that just raised $4 million in funding--has created a nifty app called Window Shopper.

Window Shopper is a browser add-on that's available for IE and Firefox. The extension is quite simple: if you're shopping for an item within any of the hundreds of available stores, a "See Similar" button will appear next to the photo of the item. Clicking the button brings up a bubble (your virtual window, as it were) that shows pics, prices, and availability of similar products.

Just how similar the comparison items are varies, though. For instance, the KitchenAid stand mixer I searched for on Target.com populated a selection of the exact same product from across various sites (as shown in the screenshot above). However, a comparison for a pair of shoes on Nordstrom's Web site produced rather different results.

In other words, the Window Shopper app may give you directly competing listings for the item you're interested in, or it may populate a list of similar (but different) products, possibly even from the same site. Thus, the usefulness varies depending on what exactly you're looking for: a better price or similar items. There doesn't appear to be a way to tinker with settings to focus in on what you need.

The other issue is that it doesn't work on all sites (Zappos being a prime example), and the functionality doesn't activate if, say, there's a video instead of a still image in the main product slot (as with the Kindle on Amazon). Still, Window Shopper's still in beta--and it's free--so these are a minor complaints, really. It's worth checking out if you do a lot of online shopping.