Wow, yea, if you're jailbroken you need to go get this app, and erase any of those barcode scanner apps you downloaded in the app store. No need to take pics with this, works just like a bar code scanner you see in stores, no idea how they did this!
Occipital RedLaser
YouTube - RedLaser 2.0: Realtime iPhone UPC barcode scanning
Occipital RedLaser
YouTube - RedLaser 2.0: Realtime iPhone UPC barcode scanning