How annoying are those little stickers on your fruits and veggies? Well those stickers serve an important purpose: the numbers tell you if you're apple's been conventionally grown, genetically-modified or organic. Who knew?

The numbers are called price look-up (PLU) numbers and have been used by supermarkets since 1990 to make check-out and inventory control easier, faster, and more accurate, states the International Federation for Produce Standards.

Here's the deal:
Conventionally-grown: You'll see a 4-digit code between 3000 and 4000
Genetically-modified (GM): Add an '8' in front of the code, e.g. 84011
Organic: Add a '9' in front of the code, e.g. 94011

If you're curious to learn more about GM foods, the Human Genome Project, a joint effort between the U.S. Department of Energy and the National Institutes of Health, has a good list of pros and cons. Similarly, here's some helpful info on organic foods reported by WebMD.

If you can't remember if you picked up an organic Fuji or a conventional Gala, now you'll know where to look.

Images obtained from Flickr (Ping News, Crusader, Knittingskwerlgurl)