Amazon subsidiary A9 has just launched the Flow iPhone app. It's yet another visual shopping aid: you point it at a product, and it looks it up and gives you a price and an ordering link.
The difference is that Flow is more real-time and more fun to use than other apps, including the Amazon app and eBay's RedLaser. Just point it at a boxed item and it will recognize it and pop up a "buy" link. If you do nothing, the link will just fade into your log of scanned items. Keep pointing your phone at products, and it just keeps collecting links. It's like the Furni scene in "Fight Club" come to life.
For things that the image recognizer doesn't pick up, you can scan the bar code in the same way, and you don't have to tell the app what you're doing. Just hold your phone's camera mostly still for a moment while pointing at a product, and if the item is sold at Amazon, it'll get added to your log. (If it's not on Amazon, it doesn't save it.)
The recognizer seems faster and more tolerant of operator sloppiness than other scanner apps. You don't have to hold very still or align the camera at a right angle to what you're pointing it at. It's not like it will pick up multiple items as you just walk by them, but it's faster and more intuitive than other apps of the type.
For lowlifes who like to saunter through bookstores to get ideas on what to buy later (and cheaper) online, this is the ultimate stealth app to kill your local businesses. And yeah, I've done that. Sorry. I don't feel so bad about using scanner apps inside a Best Buy, though. Their prices are ridiculous.