I've been interested in playing with QR codes, and how they might be applied to my work at CISTI. Recently, I found a useful tip from Lifehacker showing how to create a bookmarklet that will make a QR code of the current web page... useful if you want to transfer the current page on your desktop/laptop to your phone for mobile reading. It's a lot more convenient than emailing yourself the URL.
It's dead simple, making use of Googles chart API's. Just make a bookmark in your toolbar with the following as the location information:
javascript:void(window.open('http://chart.apis.google.com/chart?cht=qr&chs=150x150&chl='+encodeURIComponent(top.location.href)+'&chld=H|0','qr','width=155,height=155'));