Good resource for the Bringhurst-y web designer.
I did this back when I was with Gritty, which was like 3+ years ago. I'm pretty gratified they're still using this design, which has its quirky elements.
A porting of Robert Bringhurst's indispensable reference and guide to typography for use with CSS and (X)HTML. Sporadically updated, but worth reading.
Very slick implementation of a browser-agnostic set of layout tools.
I've seen this idea before - i think there was a plugin for Firefox that you could use on an entire page - but this is a really, really classy implementation of way to inspect a particular element in a webpage.
Somewhat cryptic, but an amazing overview of projects. Also they're located only like a block away from my office. Probably I've seen them in Burritoville or Atomic Wings.