I’m been using a handy JavaScript function to extract blockquote sources from the “cite” attribute and put it at the bottom of the quotation, and I’ve done something similar to make image captions from the image “title” attribute.
So I decided to put it into a WordPress plugin so others could do the same. The Filosofo JavaScript Extract plugin is incredibly simple to install: just upload it into your WordPress plugins folder and activate it from the admin control panel. Under Options > Extract Sources and Captions in the admin panel, you can configure it for your needs. Check it out and give me some feedback.