I assume they use Amazon to get EAN->item mapping which is against the amazon TOS. If they don't I love to know what they do use.

[1] - http://code.google.com/p/zxing/

[2] - http://redlaser.com/SDK.aspx

If they're doing something really clever to read these barcodes it makes some sense to not just give it away. The Apache licence does give them that option.

There are many surprising things about RedLaser's success, but technology isn't one of them. I agree with OP that apparent violations of licensing (access to Amazon.com via mobile is not allowed) are surprising. Most surprising to me is how well RedLaser has sold given that barcode scanning was antiquated over a year ago by products like SnapTell. Why scan a UPC code when you can just take a picture of the cover of a book and have the product found just as fast, with as good or better accuracy? No matter if your photo is blurry, or badly lit, or out of focus, or only grabs a part of the book's cover...

Surely the error rate of that compared to bar codes is much higher. For common products Im sure it works just as well but bar code scanning doesn't degrade for edge cases in the same way.

(Disclosure: I have nothing whatsoever to do with SnapTell, but I have been consistently impressed with the technology.)

"WARNING: 10/14/2009 The RedLaser SDK currently uses an unpublished function to access video frames. Very recently, others have indicated that this will likely lead to rejection of any application using this function, including any application with the RedLaser SDK. We are working hard to find a solution, as we believe there is great potential for this technology on the iPhone. Please take this into account when considering use of the RedLaser SDK."

So they probably analyze a lot of different video frames before finding an accurate one.

The main camera app does this too.

http://www.redlaser.com/Next.aspx

http://en.wikipedia.org/wiki/Cuecat

How?

Many retailers do not allow pictures to be taken in their stores, something that is very loosely enforced, but is enforced nonetheless.

One time I needed to take a pic of the description of a product in Home Depot so I wouldn't forget. Told the associate that and he said we don't allow pictures in our store, regardless of the reason. -- I took it anyway ;)

Now, with everything else facing retailers, especially the cost of payroll, I doubt they will fight too hard, but don't be surprised if it comes up in their training of employees more often and encourage those employees to enforce it more often.

I suppose it's technically taking a picture, but you could argue that you're not pressing the camera button, so you're not really taking a picture.

That is the correct way to deal with the situation. If they ask you to leave, just buy whatever you were in the store for at half the price at Amazon. You don't need them, they need you.

1) scan coupon barcodes, ideally using video (1-2 seconds per full page of coupons in one of those mailers?), beeping only for those you ought to keep based on what you buy and/or how good of a coupon it is.

2) automatically generate shopping list, based on coupons + what you normally buy.

3) Profit! (Well, less cost; potentially much less cost, given how many coupons there are out there, doubling, store coupons matching mfg ones, etc.)

3a) Optional: scan product barcodes as you're shopping, automatically crossing them off the list, indicating the coupon savings you should get, and also reordering the list based on what grocery department you're in...