A QR-Code is a form of barcode (which you can find on almost anything you buy at the supermarket) that has the ability to store different types of information. Such as: Alphanumeric text, a website URL, a phone number and a SMS text message. Once the barcode is generated, it can be printed and scanned with a QR-Code reader. Like a cellphone camera, and decoded with an app on the phone. Like the app “RedLaser” for iPhone.
A simple (Non-Commercial) way to generate your own Qr-Code, is to use the Kaywa QR-Code generator at http://qrcode.kaywa.com. From there you can generate a QR-Code containing all the types of information i expressed above. Then you can print it and put it on posters for example, as a form of link to your website. The user, using a reader-app on their phone, will be directed to the website when the code is scanned.