So how might QR codes (or other coding technologies) be used?
I did some research: The basic process involves the user taking a picture of the code with a cellphone with internet services enabled. The phone is loaded with special software that processes the picture and connects the user to a specific phone web-site or to a specific sms code. This opens up an interesting set of possibilities:

- Instantly watch a movie trailer from an movie ad / review in a newspaper
- Buy tickets from a movie poster or newspaper
- Sample a song from the CD ad, review or cover; find concert dates and times and buy tickets
- Buy the book after reading a review (could be from a publisher's ad next to the book review)
- Watch a how-to video linked to a recipe or product
- Get a shopping list for a recipes from the paper
- Watch a virtual tour and obtain pricing from a real estate ad or sign
- Enter a contest without mailing anything or logging-on from your home PC
- Purchase items from a mail-order magazine directly from the magazine
- Compare prices in a retail store
- Get an in-store coupon
- Find a lower price
- Get directions and a coupon from a poster at a bus stop
- Acquire real time pricing on airfare from your home city in a magazine ad
- Acquire a vehicle history report from a license plate
- Acquire your medical history from a prescription bottle
- Acquire your doctor recommendation from a prescription bottle
- Text-to-win without entering a long stream of numbers
- Acquire a patient’s medical history from a single barcode
- Click on a code to instantly report a problem

There are several competing coding standards as this is a great way to simplify the user interface to data services on a phone. Here is a link to an interesting summary of the coding technologies and applications in this area (it was the starting point for my list) http://www.trendwatching.com/trends/infolust.htm.