Back in February I created a Safari Extension to generate QR codes from the current URL. I've just completed coding an alternate version for Google's Chrome Browser.
When installed, the extension creates a new button on the browser toolbar. Clicking the button will open a popup containing a QR barcode generated from the URL of the current open tab. The barcode can then be scanned by any compatible device.
You can get the QR Code Extension for Google Chrome from my downloads page