Check the ingredients label on a food product, and there'll likely be a dozen words you can't recognize—causing havoc for vegetarians. I know how bad it is, I'm one of 'em.
Developer Faizal Mohammed has created two iPhone apps—one for veggies, one for those who follow Islamic law and only eat halal food. It's pretty easy, much like the barcode scanners we've seen before—hold the iPhone up to the ingredients label, take a photo, and then the scanner apps will detect any nasty food that you should be avoiding. I'm not just talking saturated fats either, as it'll check each additive against a database of vegetarian and halal foods and if something doesn't match up (indeed, if it's not kosher), then it'll alert you to put that bacon-hiding cupcake down.
The apps are only compatible with iPhone 3GSes as you'll need autofocus to ensure all the ingredients can be detected, but never fear if you've got an older iPhone, as you can still search the database for any words you're unfamiliar with. $2 each. [iTunes for vegetarian app, iTunes for halal app, via Recombu]