Works great. Needs info for NoScript users, though. :) Rated 4 out of 5 stars

It works great, once I got it working. With NoScript installed, the addon simply brought up a window where you could type text, but the button did nothing.

Once I visited, and permanently unblocked, http://www.qrutils.com/ then this addon works again. :) (You appear to be pulling from your site, live, to create the QR code, I assume?)

This review is for a previous version of the add-on (1.06.2). 

Server based

Yes, the QR Code image is generated on the server. Next version of the add-on will be client based and works completely offline.

Instantly a must-have Add-On for the smartphone era! Rated 5 out of 5 stars

I often need to transfer a link to my smartphone to read on later or send the link via SMS. Mozilla Sync also transfers open tabs to MY devices, but sometimes i just want to share an open tab with a friend before we quit the session.
QR Code Image Generator does just that without frills - offline and without restarting Firefox! And that means:
All stars, webdevmedia!

Wishlist: I'd like to transfer notes and custom text from the Awesome Bar! HTML text fields aren't suitable as of now.
Wishlist: Maybe a Thunderbird version could transfer events and contacts?
PS.: Cartwheeler: +1. Also looking forward to using context menu instead of the icon.
PPS.: Daminite's problem does not occur for me: Icon stays where i put it after restart.

This review is for a previous version of the add-on (1.05.1). 

new version

I have uploaded a new version that's include a hotkey CTRL-ALT-Q and item in context menu to quickly see QR Code.

Looking good Rated 4 out of 5 stars

It does what its supposed to and the only complaint I've got so far is that no matter where I move the button the next time I start up Firefox its back on the add-on bar. If I go into customize mode it will return to the place I put it.

This review is for a previous version of the add-on (1.05).