I just pushed Firefly 1.1.0 (code) to Rubygems containing a very nice new feature: QR Codes.
Why would you care? Well, almost anything can scan QR Codes nowadays. Simple add .png to the end of your shortened URL and you’ll get a nice QR Code that you can print or embed on somewhere on the web. Give it a try: http://aj.gs/2Y.png
Simply scan the image and it will yield your short URL, ready for use.