There is a plugin for the Firefox browser called Mobile Barcoder. Once installed, you can automatically generate a QR code for the current page, and/or any link on the page (right-click, generate code), or select text on the page and generate a QR code for the text.
You can add Mobile Barcoder to the Chrome browser also, but it only generates a QR code for the current page.
Ripping audio (mp3) from a YouTube video? When I am driving around, and have low bandwidth, videos pause frequently on my iPad. I was listening to some TED Talks and realized that for some presentations, the video wasn’t necessary, just the audio. So I googled for tools and found several (the one below is online) that would rip the audio from a video. The mp3 audio file is much smaller than the video, and usually will stream or play even in low bandwidth areas.
I’ve installed portable versions of my favorite browsers on a USB (flash) drive. I added the Mobile Barcoder plugin. That way, I can plug my flash drive into a PC, laptop or presentation podium in class, open my browser, and push QR codes to my audience (students). That’s even if my school doesn’t have Firefox or Chrome installed.