What are these bar codes?
These square bar codes are called QR Codes (or Quick Response codes), and can be scanned using your mobile device's camera, through one of these Free QR Code reader mobile apps.
The first step is to download one of these recommended apps below, and then open up the application, and follow instructions to use your mobile device's camera to scan the QR Code.
Once it reads the bar code, it will show you a URL, phone number, video, text message, picture, etc.
Enjoy!
iPhone QR reader
QRafter: http://itunes.apple.com/app/qrafter-qr-code-reader-generator/id416098700
RedLaser: http://itunes.apple.com/app/redlaser/id312720263?mt=8
Android QR reader
Google Goggles: http://market.android.com/details?id=com.google.android.apps.unveil
QuickMark: https://market.android.com/details?id=tw.com.quickmark
Blackberry QR reader
QR Code Scanner Pro: http://appworld.blackberry.com/webstore/content/13962?lang=en
My PIN Barcode: http://appworld.blackberry.com/webstore/content/25507?lang=en