It can be a real pain in the butt to go from browsing a Web page on your desktop or laptop to pulling up said page on your mobile phone. The process usually involves texting or emailing the URL to yourself or, if you're a real masochist, manually typing in the URL using your phone's built-in keyboard (or worse yet, T9-based keypad). Even converting the URL to a bit.ly or a goo.gl link still requires you to actually spend time fidgeting with your phone to get to the page. No matter what, this process just isn't very fun.
Not very fun, that is, until I stumbled across the Mobile Barcoder add-on for Firefox. With but the quick hit of a button, you can convert any Web page you're looking at into one of those neat cube QR codes. Depending on your phone, you can then use a built-in or downloaded application to scan said QR code directly from your monitor. Without a single press of a letter or number button, you'll have the page you were just looking at right in your phone's mobile browser.
The only problem with said add-on is that, in its current form, it doesn't work quite well. The add-on previously used a Nokia service to generate said QR codes. That service has apparently up-and-died, but fear not--an industrious developer has built a spin-off add-on that calls up Google in place of Nokia for the QR codes. I only mention this as said fix isn't hosted in the Mozilla Add-on library, and I know that some people can be a little suspicious about integrating add-ons that don't come directly from Mozilla's main site.