FoodScanner is an iPhone app that lets you scan a barcode and it then tells you about its nutritional info. Whats frustrating is that I had this idea over a year ago, the idea was that you scan an item, enter how much of it you ate, then the app keeps a running daily total of the amount of GDA of calories, fats, salts and more.
I didn't chase it up as although I knew it possible to read a barcode from an image, it would of been difficult to tally the code to a specific item as each store has its own identification numbers.
Ah well, im sure now the idea has been proven we will be seeing Tesco, Sainsburys etc bringing out their own "measure your nutritional input" iPhone app!