Google Charts is my hero yet again. This time, I happened to notice that they have a chart in their API for QR Codes. Considering I was just searching google for a PHP class to do this, I was pretty ecstatic.
To implement, I made a quick line of jQuery to generate my QR Codes. Of course, I did this after the page loaded :) My goal was to generate a QR code for the page that the user is currently viewing. Pretty simple:
$("#qrImage").attr( 'src', 'http://chart.apis.google.com/chart?chs=150x150&cht;=qr&chl;=' + escape(window.location.href) + '&choe;=UTF-8' );
You can find all of the details and other parameters here: http://code.google.com/apis/chart/docs/gallery/qr_codes.html