Due to Ajaxian recently featuring my CiteDrag JavaScript library and a suggestion in the comments, I went ahead and made a CiteDrag UserScript that applies CiteDrag to every website and a WordPress plugin that includes CiteDrag on every page of a WordPress-powered website. If you’re using Firefox, you can install the UserScript with Greasemonkey.
You may be thinking that if you visit a page that already uses CiteDrag and have the userscript installed, that the citations would be doubled. This won’t happen though because CiteDrag stores the original data for the text/html and text/plain data types in the text/x-original-html and text/x-original-plain data types. If the UserScript detects that these data types are set, it will use them instead of the already-cited data.