Calories do count, and if you are among those who keep track of your daily intake and want an easy way to log what you eat, FoodScanner [iTunes link] may be just the iPhone app for you.
On a trip to the grocery store or just your fridge, FoodScanner reads the bar code and matches it to a large database of food items. If the app is successful in finding a match, you'll get the product name, amount of calories in a single serving, fat, carbohydrates, and protein content. You can that information to a daily list to keep track of what you are eating, without the pain of doing it all on pencil and paper.
While on a trip to my local Safeway, the bar code recognition worked really well. It just took a second or so to capture the info, and then match it to a database claiming to list over 200,000 food items.
In many cases, the scan returned several items, but it was a simple task to select the correct item by name.