Fast QR Code Generator от Sarah Av.

Fast QR Code Generator is a handy addon that generates QR code from any text (URL, message, number, etc.). Simply open toolbar popup to view the QR code.

Some features:
a. One click QR code generation right from your browser toolbar.
b. Generated code can be sent to any device with a camera and QR reader.
c. Stores all visited tab URLs.
d. Available for all browsers (Chrome, Firefox, and Opera)

Some useful notes:
1. To use this extension you need a QR code reader installed on your cellphone.
2. There are a ton of QR code scanners for cellphones such as QR Droid™ for Android and QR Reader for iPhone for iOS.