Smartphone users will no doubt have encountered an app of some sort that supports barcode scanning.

So what is it and how can it change the way we shop?

There are a host of price comparison barcode scanning apps available for iOS and Android devices, Red Laser and Barcode Scanner to name but two.

But we are starting to see more big brands integrate scanning technology with their smartphone applications.

Online retail giant Amazon has launched an app for the iPhone that allows users to compare in-store product prices with those from and its affiliated merchants. By scanning a products barcode, photographing a product, or even saying its name into the handset, Amazon will instantly display pricing information. The item can then purchased through Amazon’s ‘one-click’ ordering system within the app.

Tesco have also added a barcode scanner to their official app. By scanning a grocery item it automatically places it in your online shopping basket ready for their next online shop. So if you’re running low on juice, scanning the items barcode will automatically place it in your online basket.

eBay are implementing barcode scanning too. Using RedLaser technology, users can scan a  items barcode in-store and then automatically access eBay listings of the product on the marketplace. Sellers can also use the scanning technology to quickly scan and list items.

This week, Two Amazon alumini, Blake Scholl and Jason Crawford have announced a much anticipated update for their iPhone app – Barcode Hero.

Originally launched back in August, version 1.0 of the application allowed users could scan barcodes on products, leave short product comments and give their reviews. In the style of Foursquare, users could also become king or queen of any of the 5,000 different product categories.

Version 2.0 of Barcode Hero sees a system based heavily on recommendations. For example, if you’re in a supermarket pondering wine options, you can scan a bottle of to see reviews on that bottle and other highly recommended wines in the same category, according to the community.

In the spirit of barcode scanning, there’s also a price comparison feature that will let you know if you can get it cheaper elsewhere.

As more people cotton on to price comparison apps, it could spell big trouble for already struggling highstreet stores.