This is amazing: RedLaser on the iphone will instantly scan any barcode and look up the product on amazon and google product search, showing you where you can get the best price. The entire process takes less than 2 seconds, and it works flawlessly. This is not simply a must-have app; it's a reason to buy an iphone.
And of course finding the lowest price is just one of the things you can do: you can check for book and dvd reviews, put together a shopping list by scanning stuff in your fridge - the possibilities are endless. The developer has even made the SDK available to other application developers, which means that this is just the beginning.
Take me to the next level.