I'm a huge fan of QR Codes. If you've never heard of QR Codes, they are 2 dimensional "Quick Response" matrices that allow their contents to be decoded at high speed. QR Codes storing addresses and URLs may appear in magazines, on signs, buses, business cards, or just about any object that users might need information about. Users with a camera phone equipped with the correct reader application can scan the image of the QR Code to display text, contact information, connect to a wireless network, or open a web page in the phone's browser. I like QR Codes so much that I use them on my business cards:
Lately these codes have been getting a lot of press so I thought I'd link to the articles:
Why QR Codes Are Poised to Hit the Mainstream From Mashable Today, 7/20/2010
12 Clever Social Media-Friendly Business Cards also From Mashable 7/13/2010
Explore a Whole New Way to Window Shop with Google and Your Mobile Phone From The Official Google Blog 12/7/09
There has also been talk about Foursquare and Facebook using QR codes to make it easier for users to check in.
If you've got any example of how you are using QR codes to promote your business, please let us know in the comments.