I’ve increased the line-height and p.margins slightly on this blog, inspired by this interesting article from A List Apart about improving the reading experience of long text on the web.
Of course, none of you that read through an RSS reader might see it. And in this particular case, I’m not sure this line height is actually right for this page. I’m no designer. Although I could probably do something decent if I had more control over all the page elements than this wordpress.com-hosted blog convenienty gives me.
But it’s an interesting article. I am definitely realizing lately that design matters for useability, in general. David Walker’s done a great job with Xerxes, and I’m trying not to mess it up as I add features. The right proportion of white space to content (neither too much nor too little; in terms of margins, line-height, padding, etc) can make a huge difference in the experience of usability. Sadly, few of us have designers on staff at our libraries.
Bibliographic Wilderness 
You could take the line-height here down a smidge and still be okay. Maybe consider upping the font-size a bit and widening the content column to match?