You see them all over the place, those square barcode looking things you're supposed to scan with your phone and magic will happen. They're called QR codes, and they're actually pretty useful when used right. Real estate agents, for example, have started putting them on "for sale" signs. Take a picture of one with your phone, and it'll send you to the listing on the web, a great way to reduce the amount of paper flyers.
The restaurant business has also taken note of the technology, but haven't quite wrapped their heads around how to use it. Too many menus now come with a QR code which, when scanned, takes you to something completely useless.
There is probably more than one way to use the codes properly, but as a baseline, this is what we expect:
Have the code send us to a web site displaying your menus. That way we can bookmark the page with our iAndroid webPhoneOS 7 phones and keep quick on-the-go access to your ever-changing menus.
It's those little things that matter; many of us like to check menues before going anywhere. Scanning a QR code with a phone is easy; typing in a 70 character long URL is not.
It's one of those things that just kind of makes sense. (To us at least.)
Also, there's no magic to generating QR codes -- there are plenty of options on the web.