While surfing the web I found a page where I learned that blockquote tags have the attributes cite (URI for source document) and title. They seemed like perfect candidates for displaying as a link at the bottom of the quote. So, I went searching.
The first thing I found was a blog post about Dynamically labeling blockquotes with CSS. This seemed like a good idea, but had the drawback that the link wasn’t clickable. But in a comment I found a link to a blog post, Blockquote citations, which implemented what I wanted using javascript.
So I downloaded the javascript, modified it a bit to allow the title attribute to be used as link text and it’s now fully operating.
If you wish, you can download my slightly modified version. But all credit should go to Simon Willison.
Want to see it in action? Here goes
I’m originally from a small town in the north of Sweden called PiteĆ„.
Produced from the following code
<blockquote cite="http://ejohansson.se" title="Erik Johansson"> I'm originally from a small town in the north of Sweden called PiteƄ. </blockquote>

This is perfectly lovely. Good job to you both.