Now that we're closing in on the holiday season, you absolutely must have a bar code scanner. These apps are tremendously popular, and for good reason. You're in a store, you find something you like, you scan the bar code with your iPhone's camera, and then you find out where you can buy it for the lowest price. Typically these apps are location aware, in case you want to buy it at a nearby store. And typically, they also have maps and directions that show you how to get to the store with the lowest price. And — they're free! Why would anyone go without one of these? Shop Savvy Barcode Scanner just came out with a completely revamped 4.0 version. It looks to be one of the most popular. Also available is Red Laser, the venerable app that introduced this genre on the iPhone. And Bakodo is another good option.

Barcode Scanning Pioneer
Thanks for the mention. Just a point of clarification: ShopSavvy pioneered this particular space back in 2008 when we won Google's Android Developer challenge. The RedLaser guys took our idea to the iPhone in 2009 (once Apple agreed to let us all use private camera APIs).
Thanks for the input
Thanks, Alexander, for letting me know. I've edited my post so that it specifically says that Red Laser pioneered it on the iPhone.
Jim
barcode scanners
Both Shop Savvy and Red Laser have good features. Neither one find matches all the time and only show pictures of products part of the time. Sometimes one scans better than the other depending on lighting. I use both and would not be without either one. I am impressed by both products.
Thanks for your comment. I
Thanks for your comment. I may write about these for our magazine.
JIm