Hurrah once more!
That w3schools (http://www.w3schools.com/) is pretty decent. I've now concocted an XSL stylesheet for this feed, so visiting its URL in a (good) web browser should display it as a nice page.
I managed to cajole XML namespaces into doing what I want with a little help from a random blog entry (http://today.icantfocus.com/blog/archives/entries/000430/) by Christopher H. Laco, and his one-size-fits-all feed stylesheet. Those who are interested can have a gander at my resulting stylesheet (http://purl.org/mooquackwooftweetmeow/weblog.xsl.xml).
Next job: rig up a klip.