Code Nazis
Holovaty (and probably Mark Pilgrim and Zeldman too) is a Code Nazi, checking your markup for validity, bloat, deprecated elements, code:content ratio. Perhaps I should call them a Valid Markup Advocates--anyway, the point is that they're standing up for good coding practices which will ultimately make it easier (and cheaper) to publish and access information online. It's also cool that one's choice of font over span is now a political act which shows you are either down with web standards and the W3C, or just kind of oblivious.
GetContentSize: Even though code:content is a loose metric, GetContentSize is still a great tool for exposing overweight markup and/or abysmally low text content. It has to be applied intelligently as well--a 50% code:content ratio might be a good target for a news site or a blog, while 20% might be acceptable for a business or government. Any page that presents tabular data (e.g. stock quotes) is going to take a hit since tables require more markup.

