qr code is about easily passing data to your smart phone.
The most common application is give url to your phone. android 2.2 got a feature to push links from chrome to android phone.
with qrcode, you can do it from any browser to any smartphone.
One could write an plugin for that... one js including all what is needed. display a small icon on the page. when the user click on the icon, a large qrcode open, and the user can scan it and go on on its phone.
https://github.com/jeromeetienne/webglmeeting/issues/2