Price Check by Amazon -- free app lets you find prices via voice, bar code, photo, or product name

If you're shopping and wonder whether the item you're considering could be more cheaply purchased via Amazon, a new app helps you do just that. Price Check by Amazon (free) lets you search for the product you have in mind in four different ways: you can say the name of the product, use the iPhone's camera to read the bar code, take a photo of the item, or enter the name of the product. The app uses the same voice recognition technology that powers the popular Dragon NaturallySpeaking. (iPhone 4 and 3GS only)