Smartphones have the capability to scan and read QR codes or Scan Tags with the click of a camera.
If you are listed on Google Places and Google Maps, Google has automatically generated a QR for you. Put this QR on your business card, brochures or in your print ad or poster and someone scanning it will land on a map for the location of your business.
I use both types. A colorful Scan Tag on my business card always raises questions People ask what it is, how it works and then more discussion about my services. A QR on a product flyer (one of my books) links directly to the purchase page. An associate uses her scan tag to link to a registration page for events, and a real estate agent uses his QR on his signs to link to web pages showing the details of his listings.
All you need is your computer to generate the QR codes or Scan Tags and then be creative on how you use them. You can create a QR or Scan Tag for simple text, a URL, an email message, an SMS or MMS, a phone number, or a location. (http://www.qr-barcodes.com/online-generator)
With a Microsoft Scan Tag you can get reports of how many times your tag was scanned and from what geographic area. (http://tag.microsoft.com/)