Userscripts.org

Nice idea. Providing a QR of the currently loaded page would be also nice, since one normally finds a page interesting by first inspecting it, and then decides to capture its url, same way as with bookmarks. The page's code could be displayed when the mouse nears the edge of the page, or upon pressing some key combination, of even through a GM menu command or ordinary bookmarklet.

There is a script by Brian Short at http://userscripts.org/topics/23121 which generates the code for the current page.

Google provides a QR code generator, too.

http://code.google.com/apis/chart/types.html

Perhaps, the script could be modified to randomly or cyclically choose between Nokia and Google, to balance the load. I think this is the way the Google string would have to be scripted:

var dst = 'http://chart.apis.google.com/chart?cht=qr&chl=' + escape(src.href) + '&choe=UTF-8&chs=100x100';